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diff --git a/doc/texinfo.txi b/doc/texinfo.txi new file mode 100644 index 0000000..374ebfd --- /dev/null +++ b/doc/texinfo.txi @@ -0,0 +1,21234 @@ +\input texinfo.tex @c -*-texinfo-*- +@c $Id: texinfo.txi,v 1.225 2008/09/07 22:47:46 karl Exp $ +@c Ordinarily, Texinfo files have the extension .texi. But texinfo.texi +@c clashes with texinfo.tex on 8.3 filesystems, so we use texinfo.txi. + +@c Everything between the start/end of header lines will be passed by +@c Emacs's {texinfo,makeinfo}-format region commands. See the `start of +@c header' node for more info. +@c %**start of header + +@c makeinfo and texinfo.tex ignore all text before @setfilename. +@c +@c Ordinarily, the setfilename argument ends with .info. But +@c texinfo.info-13 is too long for 14-character filesystems. +@setfilename texinfo + +@c Automake automatically updates version.texi to @set VERSION and +@c @set UPDATED to appropriate values. +@include version.texi +@settitle GNU Texinfo @value{VERSION} + +@c Define a new index for options. +@defcodeindex op +@c Put everything except function (command, in this case) names in one +@c index (arbitrarily chosen to be the concept index). +@syncodeindex op cp +@syncodeindex vr cp +@syncodeindex pg cp + +@paragraphindent 2 +@c finalout + +@comment %**end of header + +@copying +This manual is for GNU Texinfo (version @value{VERSION}, @value{UPDATED}), +a documentation system that can produce both online information and a +printed manual from a single source. + +Copyright @copyright{} 1988, 1990, 1991, 1992, 1993, 1995, 1996, 1997, +1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 +Free Software Foundation, Inc. + +@quotation +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no +Invariant Sections, with the Front-Cover Texts being ``A GNU Manual'', +and with the Back-Cover Texts as in (a) below. A copy of the license +is included in the section entitled ``GNU Free Documentation +License.'' + +(a) The FSF's Back-Cover Text is: ``You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom.'' +@end quotation +@end copying + +@dircategory Texinfo documentation system +@direntry +* Texinfo: (texinfo). The GNU documentation format. +* install-info: (texinfo)Invoking install-info. Update info/dir entries. +* texi2dvi: (texinfo)Format with texi2dvi. Print Texinfo documents. +* texi2pdf: (texinfo)PDF Output. PDF output for Texinfo. +* pdftexi2dvi: (texinfo)PDF Output. PDF output for Texinfo. +* texindex: (texinfo)Format with tex/texindex. Sort Texinfo index files. +* makeinfo: (texinfo)Invoking makeinfo. Translate Texinfo source. +@end direntry + +@c Before release, run C-u C-c C-u C-a (texinfo-all-menus-update with a +@c prefix arg). This updates the node pointers, which texinfmt.el needs. + +@c Set smallbook if printing in smallbook format so the example of the +@c smallbook font is actually written using smallbook; in bigbook, a kludge +@c is used for TeX output. Do this through the -t option to texi2dvi, +@c so this same source can be used for other paper sizes as well. +@c smallbook +@c set smallbook +@c @@clear smallbook + +@c If you like blank pages, add through texi2dvi -t. +@c setchapternewpage odd + +@c Currently undocumented command, 5 December 1993: +@c nwnode (Same as node, but no warnings; for `makeinfo'.) + + +@shorttitlepage GNU Texinfo + +@titlepage +@title Texinfo +@subtitle The GNU Documentation Format +@subtitle for Texinfo version @value{VERSION}, @value{UPDATED} + +@author Robert J. Chassell +@author Richard M. Stallman + +@c Include the Distribution inside the titlepage so +@c that headings are turned off. + +@page +@vskip 0pt plus 1filll +@insertcopying + +@sp 1 +Published by the Free Software Foundation @* +51 Franklin St, Fifth Floor @* +Boston, MA 02110-1301 @* +USA @* +ISBN 1-882114-67-1 @c for version 4.0, September 1999. +@c ISBN 1-882114-65-5 is for version 3.12, March 1998. +@c ISBN 1-882114-64-7 is for edition 2.24 of November 1996. +@c ISBN 1-882114-63-9 is for edition 2.20 of 28 February 1995. + +@sp 1 +Cover art by Etienne Suvasa. +@end titlepage + + +@summarycontents +@contents + + +@ifnottex +@node Top +@top Texinfo + +This manual is for GNU Texinfo (version @value{VERSION}, @value{UPDATED}), +a documentation system that can produce both online information and a +printed manual from a single source. + +The first part of this master menu lists the major nodes in this Info +document, including the @@-command and concept indices. The rest of +the menu lists all the lower level nodes in the document. + +@end ifnottex + +@menu +* Copying Conditions:: Your rights. +* Overview:: Texinfo in brief. +* Texinfo Mode:: Using the GNU Emacs Texinfo mode. +* Beginning a File:: What is at the beginning of a Texinfo file? +* Ending a File:: What is at the end of a Texinfo file? +* Structuring:: Creating chapters, sections, appendices, etc. +* Nodes:: Writing nodes, the basic unit of Texinfo. +* Menus:: Writing menus. +* Cross References:: Writing cross references. +* Marking Text:: Marking words and phrases as code, + keyboard input, meta-syntactic + variables, and the like. +* Quotations and Examples:: Block quotations, examples, etc. +* Lists and Tables:: Itemized or numbered lists, and tables. +* Special Displays:: Floating figures and footnotes. +* Indices:: Creating indices. +* Insertions:: Inserting @@-signs, braces, etc. +* Breaks:: Forcing or preventing line and page breaks. +* Definition Commands:: Describing functions and the like uniformly. +* Conditionals:: Specifying text for only some output cases. +* Internationalization:: Supporting languages other than English. +* Defining New Texinfo Commands:: User-defined macros and aliases. +* Hardcopy:: Output for paper, with @TeX{}. +* Creating and Installing Info Files:: Details on Info output. +* Generating HTML:: Details on HTML output. + +* Command List:: All the Texinfo @@-commands. +* Tips:: Hints on how to write a Texinfo document. +* Sample Texinfo Files:: Complete examples, including full texts. +* Include Files:: How to incorporate other Texinfo files. +* Headings:: How to write page headings and footings. +* Catching Mistakes:: How to find formatting mistakes. +* GNU Free Documentation License::Copying this manual. +* Command and Variable Index:: A menu containing commands and variables. +* General Index:: A menu covering many topics. + +@detailmenu + --- The Detailed Node Listing --- + +Overview of Texinfo + +* Reporting Bugs:: Submitting effective bug reports. +* Using Texinfo:: Create printed or online output. +* Output Formats:: Overview of the supported output formats. +* Info Files:: What is an Info file? +* Printed Books:: Characteristics of a printed book or manual. +* Formatting Commands:: @@-commands are used for formatting. +* Conventions:: General rules for writing a Texinfo file. +* Comments:: Writing comments and ignored text in general. +* Minimum:: What a Texinfo file must have. +* Six Parts:: Usually, a Texinfo file has six parts. +* Short Sample:: A short sample Texinfo file. +* History:: Acknowledgements, contributors and genesis. + +Using Texinfo Mode + +* Texinfo Mode Overview:: How Texinfo mode can help you. +* Emacs Editing:: Texinfo mode adds to GNU Emacs' general + purpose editing features. +* Inserting:: How to insert frequently used @@-commands. +* Showing the Structure:: How to show the structure of a file. +* Updating Nodes and Menus:: How to update or create new nodes and menus. +* Info Formatting:: How to format for Info. +* Printing:: How to format and print part or all of a file. +* Texinfo Mode Summary:: Summary of all the Texinfo mode commands. + +Updating Nodes and Menus + +* Updating Commands:: Five major updating commands. +* Updating Requirements:: How to structure a Texinfo file for + using the updating command. +* Other Updating Commands:: How to indent descriptions, insert + missing nodes lines, and update + nodes in sequence. + +Beginning a Texinfo File + +* Sample Beginning:: A sample beginning for a Texinfo file. +* Texinfo File Header:: The first lines. +* Document Permissions:: Ensuring your manual is free. +* Titlepage & Copyright Page:: Creating the title and copyright pages. +* Contents:: How to create a table of contents. +* The Top Node:: Creating the `Top' node and master menu. +* Global Document Commands:: Affecting formatting throughout. +* Software Copying Permissions:: Ensure that you and others continue to + have the right to use and share software. + +Texinfo File Header + +* First Line:: The first line of a Texinfo file. +* Start of Header:: Formatting a region requires this. +* setfilename:: Tell Info the name of the Info file. +* settitle:: Create a title for the printed work. +* End of Header:: Formatting a region requires this. + +Document Permissions + +* copying:: Declare the document's copying permissions. +* insertcopying:: Where to insert the permissions. + +Title and Copyright Pages + +* titlepage:: Create a title for the printed document. +* titlefont center sp:: The @code{@@titlefont}, @code{@@center}, + and @code{@@sp} commands. +* title subtitle author:: The @code{@@title}, @code{@@subtitle}, + and @code{@@author} commands. +* Copyright:: How to write the copyright notice and + include copying permissions. +* end titlepage:: Turn on page headings after the title and + copyright pages. +* headings on off:: An option for turning headings on and off + and double or single sided printing. + +The `Top' Node and Master Menu + +* Top Node Example:: +* Master Menu Parts:: + +Global Document Commands + +* documentdescription:: Document summary for the HTML output. +* setchapternewpage:: Start chapters on right-hand pages. +* paragraphindent:: Specify paragraph indentation. +* firstparagraphindent:: Suppress indentation of the first paragraph. +* exampleindent:: Specify environment indentation. + +Ending a Texinfo File + +* Printing Indices & Menus:: How to print an index in hardcopy and + generate index menus in Info. +* File End:: How to mark the end of a file. + +Chapter Structuring + +* Tree Structuring:: A manual is like an upside down tree @dots{} +* Structuring Command Types:: How to divide a manual into parts. +* makeinfo top:: The @code{@@top} command, part of the `Top' node. +* chapter:: +* unnumbered & appendix:: +* majorheading & chapheading:: +* section:: +* unnumberedsec appendixsec heading:: +* subsection:: +* unnumberedsubsec appendixsubsec subheading:: +* subsubsection:: Commands for the lowest level sections. +* Raise/lower sections:: How to change commands' hierarchical level. + +Nodes + +* Two Paths:: Different commands to structure + Info output and printed output. +* Node Menu Illustration:: A diagram, and sample nodes and menus. +* node:: Creating nodes, in detail. +* makeinfo Pointer Creation:: Letting makeinfo determine node pointers. +* anchor:: Defining arbitrary cross-reference targets. + +The @code{@@node} Command + +* Node Names:: How to choose node and pointer names. +* Writing a Node:: How to write an @code{@@node} line. +* Node Line Tips:: Keep names short. +* Node Line Requirements:: Keep names unique, without @@-commands. +* First Node:: How to write a `Top' node. +* makeinfo top command:: How to use the @code{@@top} command. + +Menus + +* Menu Location:: Menus go at the ends of short nodes. +* Writing a Menu:: What is a menu? +* Menu Parts:: A menu entry has three parts. +* Less Cluttered Menu Entry:: Two part menu entry. +* Menu Example:: Two and three part menu entries. +* Other Info Files:: How to refer to a different Info file. + +Cross References + +* References:: What cross references are for. +* Cross Reference Commands:: A summary of the different commands. +* Cross Reference Parts:: A cross reference has several parts. +* xref:: Begin a reference with `See' @dots{} +* Top Node Naming:: How to refer to the beginning of another file. +* ref:: A reference for the last part of a sentence. +* pxref:: How to write a parenthetical cross reference. +* inforef:: How to refer to an Info-only file. +* uref:: How to refer to a uniform resource locator. +* cite:: How to refer to books not in the Info system. + +@code{@@xref} + +* Reference Syntax:: What a reference looks like and requires. +* One Argument:: @code{@@xref} with one argument. +* Two Arguments:: @code{@@xref} with two arguments. +* Three Arguments:: @code{@@xref} with three arguments. +* Four and Five Arguments:: @code{@@xref} with four and five arguments. + +Marking Words and Phrases + +* Indicating:: How to indicate definitions, files, etc. +* Emphasis:: How to emphasize text. + +Indicating Definitions, Commands, etc. + +* Useful Highlighting:: Highlighting provides useful information. +* code:: Indicating program code. +* kbd:: Showing keyboard input. +* key:: Specifying keys. +* samp:: A literal sequence of characters. +* verb:: A verbatim sequence of characters. +* var:: Indicating metasyntactic variables. +* env:: Indicating environment variables. +* file:: Indicating file names. +* command:: Indicating command names. +* option:: Indicating option names. +* dfn:: Specifying definitions. +* abbr:: Indicating abbreviations. +* acronym:: Indicating acronyms. +* indicateurl:: Indicating a World Wide Web reference. +* email:: Indicating an electronic mail address. + +Emphasizing Text + +* emph & strong:: How to emphasize text in Texinfo. +* Smallcaps:: How to use the small caps font. +* Fonts:: Various font commands for printed output. + +Quotations and Examples + +* Block Enclosing Commands:: Different constructs for different purposes. +* quotation:: Writing a quotation. +* example:: Writing an example in a fixed-width font. +* verbatim:: Writing a verbatim example. +* verbatiminclude:: Including a file verbatim. +* lisp:: Illustrating Lisp code. +* small:: Examples in a smaller font. +* display:: Writing an example in the current font. +* format:: Writing an example without narrowed margins. +* exdent:: Undo indentation on a line. +* flushleft & flushright:: Pushing text flush left or flush right. +* noindent:: Preventing paragraph indentation. +* indent:: Forcing paragraph indentation. +* cartouche:: Drawing rounded rectangles around examples. + +Lists and Tables + +* Introducing Lists:: Texinfo formats lists for you. +* itemize:: How to construct a simple list. +* enumerate:: How to construct a numbered list. +* Two-column Tables:: How to construct a two-column table. +* Multi-column Tables:: How to construct generalized tables. + +Making a Two-column Table + +* table:: How to construct a two-column table. +* ftable vtable:: Automatic indexing for two-column tables. +* itemx:: How to put more entries in the first column. + +@code{@@multitable}: Multi-column Tables + +* Multitable Column Widths:: Defining multitable column widths. +* Multitable Rows:: Defining multitable rows, with examples. + +Special Displays + +* Floats:: Figures, tables, and the like. +* Images:: Including graphics and images. +* Footnotes:: Writing footnotes. + +Floats + +* float:: Producing floating material. +* caption shortcaption:: Specifying descriptions for floats. +* listoffloats:: A table of contents for floats. + +Inserting Images + +* Image Syntax:: +* Image Scaling:: + +Footnotes + +* Footnote Commands:: How to write a footnote in Texinfo. +* Footnote Styles:: Controlling how footnotes appear in Info. + +Indices + +* Index Entries:: Choose different words for index entries. +* Predefined Indices:: Use different indices for different kinds + of entries. +* Indexing Commands:: How to make an index entry. +* Combining Indices:: How to combine indices. +* New Indices:: How to define your own indices. + +Combining Indices + +* syncodeindex:: How to merge two indices, using @code{@@code} + font for the merged-from index. +* synindex:: How to merge two indices, using the + default font of the merged-to index. + +Special Insertions + +* Atsign Braces Comma:: Inserting @@ and @{@} and ,. +* Inserting Quote Characters:: Inserting left and right quotes, in code. +* Inserting Space:: How to insert the right amount of space + within a sentence. +* Inserting Accents:: How to insert accents and special characters. +* Inserting Quotation Marks:: How to insert quotation marks. +* Dots Bullets:: How to insert dots and bullets. +* TeX and copyright:: How to insert the @TeX{} logo + and the copyright symbol. +* euro:: How to insert the Euro currency symbol. +* pounds:: How to insert the pounds currency symbol. +* textdegree:: How to insert the degrees symbol. +* minus:: How to insert a minus sign. +* geq leq:: How to insert greater/less-than-or-equal signs. +* math:: How to format a mathematical expression. +* Click Sequences:: Inserting GUI usage sequences. +* Glyphs:: How to indicate results of evaluation, + expansion of macros, errors, etc. + +Inserting @@ and @{@} and @comma{} + +* Inserting an Atsign:: +* Inserting Braces:: +* Inserting a Comma:: + +Inserting Space + +* Not Ending a Sentence:: Sometimes a . doesn't end a sentence. +* Ending a Sentence:: Sometimes it does. +* Multiple Spaces:: Inserting multiple spaces. +* frenchspacing:: Specifying end-of-sentence spacing. +* dmn:: How to format a dimension. + +Inserting Ellipsis and Bullets + +* dots:: How to insert dots @dots{} +* bullet:: How to insert a bullet. + +Inserting @TeX{} and Legal Symbols: @copyright{}, @registeredsymbol{} + +* tex:: The @TeX{} logos. +* copyright symbol:: The copyright symbol (c in a circle). +* registered symbol:: The registered symbol (R in a circle). + +Glyphs for Examples + +* Glyphs Summary:: +* result:: How to show the result of expression. +* expansion:: How to indicate an expansion. +* Print Glyph:: How to indicate printed output. +* Error Glyph:: How to indicate an error message. +* Equivalence:: How to indicate equivalence. +* Point Glyph:: How to indicate the location of point. + +Glyphs Summary + +* result:: +* expansion:: +* Print Glyph:: +* Error Glyph:: +* Equivalence:: +* Point Glyph:: + +Forcing and Preventing Breaks + +* Break Commands:: Summary of break-related commands. +* Line Breaks:: Forcing line breaks. +* - and hyphenation:: Helping @TeX{} with hyphenation points. +* allowcodebreaks:: Controlling line breaks within @@code text. +* w:: Preventing unwanted line breaks in text. +* tie:: Inserting an unbreakable but varying space. +* sp:: Inserting blank lines. +* page:: Forcing the start of a new page. +* group:: Preventing unwanted page breaks. +* need:: Another way to prevent unwanted page breaks. + +Definition Commands + +* Def Cmd Template:: Writing descriptions using definition commands. +* Def Cmd Continuation Lines:: Continuing the heading over source lines. +* Optional Arguments:: Handling optional and repeated arguments. +* deffnx:: Group two or more `first' lines. +* Def Cmds in Detail:: Reference for all the definition commands. +* Def Cmd Conventions:: Conventions for writing definitions. +* Sample Function Definition:: An example. + +The Definition Commands + +* Functions Commands:: Commands for functions and similar entities. +* Variables Commands:: Commands for variables and similar entities. +* Typed Functions:: Commands for functions in typed languages. +* Typed Variables:: Commands for variables in typed languages. +* Data Types:: The definition command for data types. +* Abstract Objects:: Commands for object-oriented programming. + +Object-Oriented Programming + +* Variables: Object-Oriented Variables. +* Methods: Object-Oriented Methods. + +Conditionally Visible Text + +* Conditional Commands:: Text for a given format. +* Conditional Not Commands:: Text for any format other than a given one. +* Raw Formatter Commands:: Using raw formatter commands. +* set clear value:: Variable tests and substitutions. +* Conditional Nesting:: Using conditionals inside conditionals. + +@code{@@set}, @code{@@clear}, and @code{@@value} + +* set value:: Expand a flag variable to a string. +* ifset ifclear:: Format a region if a flag is set. +* value Example:: An easy way to update edition information. + +Internationalization + +* documentlanguage:: Declaring the current language. +* documentencoding:: Declaring the input encoding. + +Defining New Texinfo Commands + +* Defining Macros:: Defining and undefining new commands. +* Invoking Macros:: Using a macro, once you've defined it. +* Macro Details:: Limitations of Texinfo macros. +* alias:: Command aliases. +* definfoenclose:: Customized highlighting. + +Formatting and Printing Hardcopy + +* Use TeX:: Use @TeX{} to format for hardcopy. +* Format with tex/texindex:: How to format with explicit shell commands. +* Format with texi2dvi:: A simpler way to format. +* Print with lpr:: How to print. +* Within Emacs:: How to format and print from an Emacs shell. +* Texinfo Mode Printing:: How to format and print in Texinfo mode. +* Compile-Command:: How to print using Emacs's compile command. +* Requirements Summary:: @TeX{} formatting requirements summary. +* Preparing for TeX:: What to do before you use @TeX{}. +* Overfull hboxes:: What are and what to do with overfull hboxes. +* smallbook:: How to print small format books and manuals. +* A4 Paper:: How to print on A4 or A5 paper. +* pagesizes:: How to print with customized page sizes. +* Cropmarks and Magnification:: How to print marks to indicate the size + of pages and how to print scaled up output. +* PDF Output:: Portable Document Format output. +* Obtaining TeX:: How to Obtain @TeX{}. + +Creating and Installing Info Files + +* Creating an Info File:: +* Installing an Info File:: + +Creating an Info File + +* makeinfo advantages:: @code{makeinfo} provides better error checking. +* Invoking makeinfo:: How to run @code{makeinfo} from a shell. +* makeinfo options:: Specify fill-column and other options. +* Pointer Validation:: How to check that pointers point somewhere. +* makeinfo in Emacs:: How to run @code{makeinfo} from Emacs. +* texinfo-format commands:: Two Info formatting commands written + in Emacs Lisp are an alternative + to @code{makeinfo}. +* Batch Formatting:: How to format for Info in Emacs Batch mode. +* Tag and Split Files:: How tagged and split files help Info + to run better. + +Installing an Info File + +* Directory File:: The top level menu for all Info files. +* New Info File:: Listing a new Info file. +* Other Info Directories:: How to specify Info files that are + located in other directories. +* Installing Dir Entries:: How to specify what menu entry to add + to the Info directory. +* Invoking install-info:: @code{install-info} options. + +Generating HTML + +* HTML Translation:: Details of the HTML output. +* HTML Splitting:: How HTML output is split. +* HTML CSS:: Influencing HTML output with Cascading Style Sheets. +* HTML Xref:: Cross-references in HTML output. + +HTML Cross-references + +* Link Basics: HTML Xref Link Basics. +* Node Expansion: HTML Xref Node Name Expansion. +* Command Expansion: HTML Xref Command Expansion. +* 8-bit Expansion: HTML Xref 8-bit Character Expansion. +* Mismatch: HTML Xref Mismatch. + +@@-Command List + +* Command Syntax:: General syntax for varieties of @@-commands. + +Sample Texinfo Files + +* Short Sample Texinfo File:: +* GNU Sample Texts:: +* Verbatim Copying License:: +* All-permissive Copying License:: + +GNU Free Documentation License + +Include Files + +* Using Include Files:: How to use the @code{@@include} command. +* texinfo-multiple-files-update:: How to create and update nodes and + menus when using included files. +* Include Files Requirements:: @code{texinfo-multiple-files-update} needs. +* Sample Include File:: A sample outer file with included files + within it; and a sample included file. +* Include Files Evolution:: How use of the @code{@@include} command + has changed over time. + +Page Headings + +* Headings Introduced:: Conventions for using page headings. +* Heading Format:: Standard page heading formats. +* Heading Choice:: How to specify the type of page heading. +* Custom Headings:: How to create your own headings and footings. + +Formatting Mistakes + +* makeinfo Preferred:: @code{makeinfo} finds errors. +* Debugging with Info:: How to catch errors with Info formatting. +* Debugging with TeX:: How to catch errors with @TeX{} formatting. +* Using texinfo-show-structure:: How to use @code{texinfo-show-structure}. +* Using occur:: How to list all lines containing a pattern. +* Running Info-Validate:: How to find badly referenced nodes. + +Finding Badly Referenced Nodes + +* Using Info-validate:: How to run @code{Info-validate}. +* Unsplit:: How to create an unsplit file. +* Tagifying:: How to tagify a file. +* Splitting:: How to split a file manually. + +@end detailmenu +@end menu + +@c Reward readers for getting to the end of the menu :). +@c Contributed by Arnold Robbins. +@quotation +Documentation is like sex: when it is good, it is very, very good; and +when it is bad, it is better than nothing. +---Dick Brandon +@end quotation + + +@node Copying Conditions +@unnumbered Texinfo Copying Conditions +@cindex Copying conditions +@cindex Conditions for copying Texinfo + +The programs currently being distributed that relate to Texinfo include +@code{makeinfo}, @code{info}, @code{texindex}, and @file{texinfo.tex}. +These programs are @dfn{free}; this means that everyone is free to use +them and free to redistribute them on a free basis. The Texinfo-related +programs are not in the public domain; they are copyrighted and there +are restrictions on their distribution, but these restrictions are +designed to permit everything that a good cooperating citizen would want +to do. What is not allowed is to try to prevent others from further +sharing any version of these programs that they might get from you. + +Specifically, we want to make sure that you have the right to give away +copies of the programs that relate to Texinfo, that you receive source +code or else can get it if you want it, that you can change these +programs or use pieces of them in new free programs, and that you know +you can do these things. + +To make sure that everyone has such rights, we have to forbid you to +deprive anyone else of these rights. For example, if you distribute +copies of the Texinfo related programs, you must give the recipients all +the rights that you have. You must make sure that they, too, receive or +can get the source code. And you must tell them their rights. + +Also, for our own protection, we must make certain that everyone finds +out that there is no warranty for the programs that relate to Texinfo. +If these programs are modified by someone else and passed on, we want +their recipients to know that what they have is not what we distributed, +so that any problems introduced by others will not reflect on our +reputation. + +The precise conditions of the licenses for the programs currently being +distributed that relate to Texinfo are found in the General Public +Licenses that accompany them. This manual specifically is covered by +the GNU Free Documentation License (@pxref{GNU Free Documentation +License}). + + +@node Overview +@chapter Overview of Texinfo +@cindex Overview of Texinfo +@cindex Texinfo overview + +@dfn{Texinfo}@footnote{The first syllable of ``Texinfo'' is pronounced +like ``speck'', not ``hex''. This odd pronunciation is derived from, +but is not the same as, the pronunciation of @TeX{}. In the word +@TeX{}, the @samp{X} is actually the Greek letter ``chi'' rather than +the English letter ``ex''. Pronounce @TeX{} as if the @samp{X} were the +last sound in the name `Bach'; but pronounce Texinfo as if the @samp{x} +were a `k'. Spell ``Texinfo'' with a capital ``T'' and the other +letters in lower case.} is a documentation system that uses a single +source file to produce both online information and printed output. This +means that instead of writing two different documents, one for the +online information and the other for a printed work, you need write only +one document. Therefore, when the work is revised, you need revise only +that one document. + +Manuals for most GNU packages are written in Texinfo, and available +online at @url{http://www.gnu.org/doc}. + +@menu +* Reporting Bugs:: Submitting effective bug reports. +* Using Texinfo:: Create printed or online output. +* Output Formats:: Overview of the supported output formats. +* Info Files:: What is an Info file? +* Printed Books:: Characteristics of a printed book or manual. +* Formatting Commands:: @@-commands are used for formatting. +* Conventions:: General rules for writing a Texinfo file. +* Comments:: Writing comments and ignored text in general. +* Minimum:: What a Texinfo file must have. +* Six Parts:: Usually, a Texinfo file has six parts. +* Short Sample:: A short sample Texinfo file. +* History:: Acknowledgements, contributors and genesis. +@end menu + + +@node Reporting Bugs +@section Reporting Bugs + +@cindex Bugs, reporting +@cindex Suggestions for Texinfo, making +@cindex Reporting bugs +We welcome bug reports and suggestions for any aspect of the Texinfo system, +programs, documentation, installation, anything. Please email them to +@email{bug-texinfo@@gnu.org}. You can get the latest version of Texinfo +from @uref{ftp://ftp.gnu.org/gnu/texinfo/} and its mirrors worldwide. + +@cindex Checklist for bug reports +For bug reports, please include enough information for the maintainers +to reproduce the problem. Generally speaking, that means: + +@itemize @bullet +@item the version number of Texinfo and the program(s) or manual(s) involved. +@item hardware and operating system names and versions. +@item the contents of any input files necessary to reproduce the bug. +@item a description of the problem and samples of any erroneous output. +@item any unusual options you gave to @command{configure}. +@item anything else that you think would be helpful. +@end itemize + +When in doubt whether something is needed or not, include it. It's +better to include too much than to leave out something important. + +@cindex Patches, contributing +Patches are most welcome; if possible, please make them with +@samp{@w{diff -c}} (@pxref{Top,, Overview, diff, Comparing and Merging +Files}) and include @file{ChangeLog} entries (@pxref{Change Log,,, +emacs, The GNU Emacs Manual}), and follow the existing coding style. + + +@node Using Texinfo +@section Using Texinfo + +@cindex Using Texinfo in general +@cindex Texinfo, introduction to +@cindex Introduction to Texinfo + +Using Texinfo, you can create a printed document (via the @TeX{} +typesetting system) the normal features of a book, including chapters, +sections, cross references, and indices. From the same Texinfo source +file, you can create an Info file with special features to make +documentation browsing easy. You can also create from that same +source file an HTML output file suitable for use with a web browser, +or an XML file. See the next section (@pxref{Output Formats}) for +details and the exact commands to generate output from the source. + +@TeX{} works with virtually all printers; Info works with virtually all +computer terminals; the HTML output works with virtually all web +browsers. Thus Texinfo can be used by almost any computer user. + +@cindex Source file format +A Texinfo source file is a plain ASCII file containing text +interspersed with @dfn{@@-commands} (words preceded by an @samp{@@}) +that tell the typesetting and formatting programs what to do. You can +edit a Texinfo file with any text editor, but it is especially +convenient to use GNU Emacs since that editor has a special mode, +called Texinfo mode, that provides various Texinfo-related features. +(@xref{Texinfo Mode}.) + +You can use Texinfo to create both online help and printed manuals; +moreover, Texinfo is freely redistributable. For these reasons, Texinfo +is the official documentation format of the GNU project. More +information is available at the @uref{http://www.gnu.org/doc/, GNU +documentation web page}. + + +@node Output Formats +@section Output Formats +@cindex Output formats +@cindex Back-end output formats + +Here is a brief overview of the output formats currently supported by +Texinfo. + +@table @asis +@item Info +@cindex Info output +(Generated via @command{makeinfo}.) This format is essentially a +plain text transliteration of the Texinfo source. It adds a few +control characters to separate nodes and provide navigational +information for menus, cross-references, indices, and so on. See the +next section (@pxref{Info Files}) for more details on this format. +The Emacs Info subsystem (@pxref{Top,,Getting Started,info, Info}), +and the standalone @command{info} program (@pxref{Top +,, Info Standalone, info-stnd, GNU Info}), among others, can read these +files. @xref{Creating and Installing Info Files}. + +@item Plain text +@cindex Plain text output +(Generated via @command{makeinfo --no-headers}.) This is almost the +same as Info output, except the navigational control characters are +omitted. Also, standard output is used by default. + +@item HTML +@cindex HTML output +@cindex W3 consortium +@cindex Mozilla +@cindex Lynx +@cindex Emacs-W3 +(Generated via @command{makeinfo --html}.) This is the Hyper Text +Markup Language that has become the most commonly used language for +writing documents on the World Wide Web. Web browsers, such as +Mozilla, Lynx, and Emacs-W3, can render this language online. There +are many versions of HTML; @command{makeinfo} tries to use a subset +of the language that can be interpreted by any common browser. For +details of the HTML language and much related information, see +@uref{http://www.w3.org/MarkUp/}. @xref{Generating HTML}. + +@item DVI +@cindex DVI output +@pindex dvips +@pindex xdvi +(Generated via @command{texi2dvi}.) This DeVice Independent binary +format is output by the @TeX{} typesetting program +(@uref{http://tug.org}). This is then read by a DVI `driver', which +writes the actual device-specific commands that can be viewed or +printed, notably Dvips for translation to PostScript (@pxref{Invoking +Dvips,,, dvips, Dvips}) and Xdvi for viewing on an X display +(@uref{http://sourceforge.net/projects/xdvi/}). @xref{Hardcopy}. + +Be aware that the Texinfo language is very different from and much +stricter than @TeX{}'s usual languages, plain @TeX{} and @LaTeX{}. +For more information on @TeX{} in general, please see the book +@cite{@TeX{} for the Impatient}, available from +@uref{http://savannah.gnu.org/projects/teximpatient}. + +@item PDF +@cindex PDF output +@cindex Beebe, Nelson +@pindex pdftex +(Generated via @command{texi2dvi --pdf} or @command{texi2pdf}.) This +format was developed by Adobe Systems for portable document +interchange, based on their previous PostScript language. It can +represent the exact appearance of a document, including fonts and +graphics, and supporting arbitrary scaling. It is intended to be +platform-independent and easily viewable, among other design goals; +@uref{http://tug.org/TUGboat/Articles/tb22-3/tb72beebe-pdf.pdf} has +some background. Texinfo uses the @command{pdftex} program, a variant +of @TeX{}, to output PDF; see +@uref{http://tug.org/applications/pdftex}. @xref{PDF Output}. + +@item XML +@cindex XML output +@cindex DTD, for Texinfo XML +@pindex texinfo.dtd +(Generated via @command{makeinfo --xml}.) XML is a generic syntax +specification usable for any sort of content (see, for example, +@uref{http://www.w3.org/XML/}). The @command{makeinfo} XML output, +unlike all the formats above, interprets very little of the Texinfo +source. Rather, it merely translates the Texinfo markup commands into +XML syntax, for processing by further XML tools. The particular +syntax output is defined in the file @file{texinfo.dtd} included in +the Texinfo source distribution. + +@item Docbook +@cindex Docbook output +(Generated via @command{makeinfo --docbook}.) This is an XML-based +format developed some years ago, primarily for technical +documentation. It therefore bears some resemblance, in broad +outlines, to Texinfo. See @uref{http://www.docbook.org}. If you want +to convert from Docbook @emph{to} Texinfo, please see +@uref{http://docbook2X.sourceforge.net}. + +@end table + +@cindex Man page output, not supported +From time to time, proposals are made to generate traditional Unix man +pages from Texinfo source. However, because man pages have a very +strict conventional format, generating a good man page requires a +completely different source than the typical Texinfo applications of +writing a good user tutorial and/or a good reference manual. This +makes generating man pages incompatible with the Texinfo design goal +of not having to document the same information in different ways for +different output formats. You might as well just write the man page +directly. + +@pindex help2man +@cindex O'Dea, Brendan +Man pages still have their place, and if you wish to support them, you +may find the program @command{help2man} to be useful; it generates a +traditional man page from the @samp{--help} output of a program. In +fact, this is currently used to generate man pages for the programs in +the Texinfo distribution. It is GNU software written by Brendan +O'Dea, available from @uref{ftp://ftp.gnu.org/gnu/help2man/}. + +@cindex Output formats, supporting more +@cindex SGML-tools output format +If you are a programmer and would like to contribute to the GNU project +by implementing additional output formats for Texinfo, that would be +excellent. But please do not write a separate translator texi2foo for +your favorite format foo! That is the hard way to do the job, and makes +extra work in subsequent maintenance, since the Texinfo language is +continually being enhanced and updated. Instead, the best approach is +modify @code{makeinfo} to generate the new format. + + +@node Info Files +@section Info Files +@cindex Info files + +An Info file is a Texinfo file formatted so that the Info documentation +reading program can operate on it. (@code{makeinfo} +and @code{texinfo-format-buffer} are two commands that convert a Texinfo file +into an Info file.) + +Info files are divided into pieces called @dfn{nodes}, each of which +contains the discussion of one topic. Each node has a name, and +contains both text for the user to read and pointers to other nodes, +which are identified by their names. The Info program displays one node +at a time, and provides commands with which the user can move to other +related nodes. + +@xref{Top,,, info, GNU Info}, for more information about using Info. + +Each node of an Info file may have any number of child nodes that +describe subtopics of the node's topic. The names of child +nodes are listed in a @dfn{menu} within the parent node; this +allows you to use certain Info commands to move to one of the child +nodes. Generally, an Info file is organized like a book. If a node +is at the logical level of a chapter, its child nodes are at the level +of sections; likewise, the child nodes of sections are at the level +of subsections. + +All the children of any one parent are linked together in a +bidirectional chain of `Next' and `Previous' pointers. The `Next' +pointer provides a link to the next section, and the `Previous' pointer +provides a link to the previous section. This means that all the nodes +that are at the level of sections within a chapter are linked together. +Normally the order in this chain is the same as the order of the +children in the parent's menu. Each child node records the parent node +name as its `Up' pointer. The last child has no `Next' pointer, and the +first child has the parent both as its `Previous' and as its `Up' +pointer.@footnote{In some documents, the first child has no `Previous' +pointer. Occasionally, the last child has the node name of the next +following higher level node as its `Next' pointer.} + +The book-like structuring of an Info file into nodes that correspond +to chapters, sections, and the like is a matter of convention, not a +requirement. The `Up', `Previous', and `Next' pointers of a node can +point to any other nodes, and a menu can contain any other nodes. +Thus, the node structure can be any directed graph. But it is usually +more comprehensible to follow a structure that corresponds to the +structure of chapters and sections in a printed book or report.@refill + +In addition to menus and to `Next', `Previous', and `Up' pointers, Info +provides pointers of another kind, called references, that can be +sprinkled throughout the text. This is usually the best way to +represent links that do not fit a hierarchical structure.@refill + +Usually, you will design a document so that its nodes match the +structure of chapters and sections in the printed output. But +occasionally there are times when this is not right for the material +being discussed. Therefore, Texinfo uses separate commands to specify +the node structure for the Info file and the section structure for the +printed output.@refill + +Generally, you enter an Info file through a node that by convention is +named `Top'. This node normally contains just a brief summary of the +file's purpose, and a large menu through which the rest of the file is +reached. From this node, you can either traverse the file +systematically by going from node to node, or you can go to a specific +node listed in the main menu, or you can search the index menus and then +go directly to the node that has the information you want. Alternatively, +with the standalone Info program, you can specify specific menu items on +the command line (@pxref{Top,,, info, Info}). + +If you want to read through an Info file in sequence, as if it were a +printed manual, you can hit @key{SPC} repeatedly, or you get the whole +file with the advanced Info command @kbd{g *}. (@inforef{Advanced, +Advanced Info commands, info}.)@refill + +@c !!! dir file may be located in one of many places: +@c /usr/local/emacs/info mentioned in info.c DEFAULT_INFOPATH +@c /usr/local/lib/emacs/info mentioned in info.c DEFAULT_INFOPATH +@c /usr/gnu/info mentioned in info.c DEFAULT_INFOPATH +@c /usr/local/info +@c /usr/local/lib/info +The @file{dir} file in the @file{info} directory serves as the +departure point for the whole Info system. From it, you can reach the +`Top' nodes of each of the documents in a complete Info system.@refill + +@cindex URI syntax for Info +If you wish to refer to an Info file in a URI, you can use the +(unofficial) syntax exemplified in the following. This works with +Emacs/W3, for example: +@example +info:///usr/info/emacs#Dissociated%20Press +info:emacs#Dissociated%20Press +info://localhost/usr/info/emacs#Dissociated%20Press +@end example + +The @command{info} program itself does not follow URIs of any kind. + + +@node Printed Books +@section Printed Books +@cindex Printed book and manual characteristics +@cindex Manual characteristics, printed +@cindex Book characteristics, printed +@cindex Texinfo printed book characteristics +@cindex Characteristics, printed books or manuals + +@cindex Knuth, Donald +A Texinfo file can be formatted and typeset as a printed book or manual. +To do this, you need @TeX{}, a powerful, sophisticated typesetting +program written by Donald Knuth.@footnote{You can also use the +@pindex texi2roff@r{, unsupported software} +@uref{ftp://tug.org/texi2roff.tar.gz, @code{texi2roff}} program if you +do not have @TeX{}; since Texinfo is designed for use with @TeX{}, +@code{texi2roff} is not described here. @code{texi2roff} is not part of +the standard GNU distribution and is not maintained or up-to-date with +all the Texinfo features described in this manual.} + +A Texinfo-based book is similar to any other typeset, printed work: it +can have a title page, copyright page, table of contents, and preface, +as well as chapters, numbered or unnumbered sections and subsections, +page headers, cross references, footnotes, and indices.@refill + +You can use Texinfo to write a book without ever having the intention +of converting it into online information. You can use Texinfo for +writing a printed novel, and even to write a printed memo, although +this latter application is not recommended since electronic mail is so +much easier.@refill + +@TeX{} is a general purpose typesetting program. Texinfo provides a +file @file{texinfo.tex} that contains information (definitions or +@dfn{macros}) that @TeX{} uses when it typesets a Texinfo file. +(@file{texinfo.tex} tells @TeX{} how to convert the Texinfo @@-commands +to @TeX{} commands, which @TeX{} can then process to create the typeset +document.) @file{texinfo.tex} contains the specifications for printing +a document. You can get the latest version of @file{texinfo.tex} from +the Texinfo home page, @uref{http://www.gnu.org/software/texinfo/}. + +In the United States, documents are most often printed on 8.5 inch by 11 +inch pages (216@dmn{mm} by 280@dmn{mm}); this is the default size. But +you can also print for 7 inch by 9.25 inch pages (178@dmn{mm} by +235@dmn{mm}, the @code{@@smallbook} size; or on A4 or A5 size paper +(@code{@@afourpaper}, @code{@@afivepaper}). (@xref{smallbook, , +Printing ``Small'' Books}. Also, see @ref{A4 Paper, ,Printing on A4 +Paper}.) + +By changing the parameters in @file{texinfo.tex}, you can change the +size of the printed document. In addition, you can change the style in +which the printed document is formatted; for example, you can change the +sizes and fonts used, the amount of indentation for each paragraph, the +degree to which words are hyphenated, and the like. By changing the +specifications, you can make a book look dignified, old and serious, or +light-hearted, young and cheery. + +@TeX{} is freely distributable. It is written in a superset of Pascal +called WEB and can be compiled either in Pascal or (by using a +conversion program that comes with the @TeX{} distribution) in C. +(@xref{TeX Mode, ,@TeX{} Mode, emacs, The GNU Emacs Manual}, for information +about @TeX{}.)@refill + +@TeX{} is very powerful and has a great many features. Because a +Texinfo file must be able to present information both on a +character-only terminal in Info form and in a typeset book, the +formatting commands that Texinfo supports are necessarily limited. + +To get a copy of @TeX{}, see +@ref{Obtaining TeX, , How to Obtain @TeX{}}. + + +@node Formatting Commands +@section @@-commands +@cindex @@-commands +@cindex Formatting commands + +In a Texinfo file, the commands that tell @TeX{} how to typeset the +printed manual and tell @code{makeinfo} and +@code{texinfo-format-buffer} how to create an Info file are preceded +by @samp{@@}; they are called @dfn{@@-commands}. For example, +@code{@@node} is the command to indicate a node and @code{@@chapter} +is the command to indicate the start of a chapter.@refill + +@quotation Note +Almost all @@ command names are entirely lower case. +@end quotation + +The Texinfo @@-commands are a strictly limited set of constructs. The +strict limits make it possible for Texinfo files to be understood both +by @TeX{} and by the code that converts them into Info files. You can +display Info files on any terminal that displays alphabetic and +numeric characters. Similarly, you can print the output generated by +@TeX{} on a wide variety of printers.@refill + +Depending on what they do or what arguments@footnote{The word +@dfn{argument} comes from the way it is used in mathematics and does not +refer to a dispute between two people; it refers to the information +presented to the command. According to the @cite{Oxford English +Dictionary}, the word derives from the Latin for @dfn{to make clear, +prove}; thus it came to mean `the evidence offered as proof', which is +to say, `the information offered', which led to its mathematical +meaning. In its other thread of derivation, the word came to mean `to +assert in a manner against which others may make counter assertions', +which led to the meaning of `argument' as a dispute.} they take, you +need to write @@-commands on lines of their own or as part of +sentences: + +@itemize @bullet +@item +Write a command such as @code{@@quotation} at the beginning of a line as +the only text on the line. (@code{@@quotation} begins an indented +environment.) + +@item +Write a command such as @code{@@chapter} at the beginning of a line +followed by the command's arguments, in this case the chapter title, on +the rest of the line. (@code{@@chapter} creates chapter titles.)@refill + +@item +Write a command such as @code{@@dots@{@}} wherever you wish but usually +within a sentence. (@code{@@dots@{@}} creates an ellipsis @dots{})@refill + +@item +Write a command such as @code{@@code@{@var{sample-code}@}} wherever you +wish (but usually within a sentence) with its argument, +@var{sample-code} in this example, between the braces. (@code{@@code} +marks text as being code.)@refill + +@item +Write a command such as @code{@@example} on a line of its own; write the +body-text on following lines; and write the matching @code{@@end} +command, @code{@@end example} in this case, on a line of its own +after the body-text. (@code{@@example} @dots{} @code{@@end example} +indents and typesets body-text as an example.) It's usually ok to +indent environment commands like this, but in complicated and +hard-to-define circumstances the extra spaces cause extra space to +appear in the output, so beware. +@end itemize + +@noindent +@cindex Braces, when to use +As a general rule, a command requires braces if it mingles among other +text; but it does not need braces if it starts a line of its own. The +non-alphabetic commands, such as @code{@@:}, are exceptions to the rule; +they do not need braces.@refill + +As you gain experience with Texinfo, you will rapidly learn how to +write the different commands: the different ways to write commands +actually make it easier to write and read Texinfo files than if all +commands followed exactly the same syntax. @xref{Command Syntax, , +@@-Command Syntax}, for all the details. + + +@node Conventions +@section General Syntactic Conventions +@cindex General syntactic conventions +@cindex Syntactic conventions +@cindex Conventions, syntactic +@cindex Characters, basic input + +This section describes the general conventions used in all Texinfo documents. + +@itemize @bullet +@item +@cindex Source files, characters used +All printable ASCII characters except @samp{@@}, @samp{@{} and +@samp{@}} can appear in a Texinfo file and stand for themselves. +@samp{@@} is the escape character which introduces commands, while +@samp{@{} and @samp{@}} are used to surround arguments to certain +commands. To put one of these special characters into the document, put +an @samp{@@} character in front of it, like this: @samp{@@@@}, +@samp{@@@{}, and @samp{@@@}}. + +@item +@cindex Paragraph separator +@cindex Blank lines, as paragraph separator +@cindex Newlines, as blank lines +Separate paragraphs with one or more blank lines. Currently Texinfo +only recognizes newline characters as end of line, not the CRLF +sequence used on some systems; so a @dfn{blank line} means exactly two +consecutive newlines. Sometimes blank lines are useful or convenient +in other cases as well; you can use the @code{@@noindent} to inhibit +paragraph indentation if required (@pxref{noindent,,@code{@@noindent}}). + +@item +Texinfo supports the usual quotation marks used in English, and +quotation marks used in other languages, please see @ref{Inserting +Quotation Marks}. + +@item +@cindex Multiple dashes in source +@cindex Dashes in source +@cindex Hyphens in source, two or three in a row +@cindex Em dash, producing +@cindex En dash, producing +Use three hyphens in a row, @samp{---}, to produce a long dash---like +this (called an @dfn{em dash}), used for punctuation in sentences. +Use two hyphens, @samp{--}, to produce a medium dash (called an +@dfn{en dash}), used primarily for numeric ranges, as in ``June +25--26''. Use a single hyphen, @samp{-}, to produce a standard hyphen +used in compound words. For display on the screen, Info reduces three +hyphens to two and two hyphens to one (not transitively!). Of course, +any number of hyphens in the source remain as they are in literal +contexts, such as @code{@@code} and @code{@@example}. + +@item +@cindex Tabs; don't use! +@strong{Caution:} Last, do not use tab characters in a Texinfo file +(except in verbatim modes)! @TeX{} uses variable-width fonts, which +means that it is impractical at best to define a tab to work in all +circumstances. Consequently, @TeX{} treats tabs like single spaces, +and that is not what they look like in the source. Furthermore, +@code{makeinfo} does nothing special with tabs, and thus a tab +character in your input file will usually appear differently in the +output. + +@noindent +To avoid this problem, Texinfo mode in GNU Emacs inserts +multiple spaces when you press the @key{TAB} key. Also, you can run +@code{untabify} in Emacs to convert tabs in a region to multiple +spaces, or use the @code{unexpand} command from the shell. + +@end itemize + + +@node Comments +@section Comments + +@cindex Comments +@findex comment +@findex c @r{(comment)} + +You can write comments in a Texinfo file that will not appear in +either the Info file or the printed manual by using the +@code{@@comment} command (which may be abbreviated to @code{@@c}). +Such comments are for the person who revises the Texinfo file. All the +text on a line that follows either @code{@@comment} or @code{@@c} is a +comment; the rest of the line does not appear in either the Info file +or the printed manual. + +Often, you can write the @code{@@comment} or @code{@@c} in the middle of +a line, and only the text that follows after the @code{@@comment} or +@code{@@c} command does not appear; but some commands, such as +@code{@@settitle} and @code{@@setfilename}, work on a whole line. You +cannot use @code{@@comment} or @code{@@c} in a line beginning with such +a command. + +@cindex Ignored text +@cindex Unprocessed text +@findex ignore +You can write long stretches of text that will not appear in either +the Info file or the printed manual by using the @code{@@ignore} and +@code{@@end ignore} commands. Write each of these commands on a line +of its own, starting each command at the beginning of the line. Text +between these two commands does not appear in the processed output. +You can use @code{@@ignore} and @code{@@end ignore} for writing +comments. + +Text enclosed by @code{@@ignore} or by failing @code{@@ifset} or +@code{@@ifclear} conditions is ignored in the sense that it will not +contribute to the formatted output. However, @TeX{} and makeinfo must +still parse the ignored text, in order to understand when to @emph{stop} +ignoring text from the source file; that means that you may still get +error messages if you have invalid Texinfo commands within ignored text. + + +@node Minimum +@section What a Texinfo File Must Have +@cindex Minimal Texinfo file (requirements) +@cindex Must have in Texinfo file +@cindex Required in Texinfo file +@cindex Texinfo file minimum + +By convention, the name of a Texinfo file ends with (in order of +preference) one of the extensions @file{.texinfo}, @file{.texi}, +@file{.txi}, or @file{.tex}. The longer extensions are preferred since +they describe more clearly to a human reader the nature of the file. +The shorter extensions are for operating systems that cannot handle long +file names. + +In order to be made into a printed manual and an Info file, a Texinfo +file @strong{must} begin with lines like this: + +@example +@group +\input texinfo +@@setfilename @var{info-file-name} +@@settitle @var{name-of-manual} +@end group +@end example + +@noindent +The contents of the file follow this beginning, and then you +@strong{must} end a Texinfo file with a line like this: + +@example +@@bye +@end example + +@findex \input @r{(raw @TeX{} startup)} +@noindent +Here's an explanation: + +@itemize @bullet +@item +The @samp{\input texinfo} line tells @TeX{} to use the +@file{texinfo.tex} file, which tells @TeX{} how to translate the Texinfo +@@-commands into @TeX{} typesetting commands. (Note the use of the +backslash, @samp{\}; this is correct for @TeX{}.) + +@item +The @code{@@setfilename} line provides a name for the Info file and +tells @TeX{} to open auxiliary files. @strong{All text before +@code{@@setfilename} is ignored!} + +@item +The @code{@@settitle} line specifies a title for the page headers (or +footers) of the printed manual, and the default document description for +the @samp{<head>} in HTML format. Strictly speaking, @code{@@settitle} +is optional---if you don't mind your document being titled `Untitled'. + +@item +The @code{@@bye} line at the end of the file on a line of its own tells +the formatters that the file is ended and to stop formatting. + +@end itemize + +Typically, you will not use quite such a spare format, but will include +mode setting and start-of-header and end-of-header lines at the +beginning of a Texinfo file, like this: + +@example +@group +\input texinfo @@c -*-texinfo-*- +@@c %**start of header +@@setfilename @var{info-file-name} +@@settitle @var{name-of-manual} +@@c %**end of header +@end group +@end example + +@noindent +In the first line, @samp{-*-texinfo-*-} causes Emacs to switch into +Texinfo mode when you edit the file. + +The @code{@@c} lines which surround the @code{@@setfilename} and +@code{@@settitle} lines are optional, but you need them in order to +run @TeX{} or Info on just part of the file. (@xref{Start of Header}.) + +Furthermore, you will usually provide a Texinfo file with a title page, +indices, and the like, all of which are explained in this manual. But +the minimum, which can be useful for short documents, is just the three +lines at the beginning and the one line at the end. + + +@node Six Parts +@section Six Parts of a Texinfo File + +Generally, a Texinfo file contains more than the minimal beginning and +end described in the previous section---it usually contains the six +parts listed below. These are described fully in the following sections. + +@table @r +@item 1. Header +The @dfn{Header} names the file, tells @TeX{} which definitions file to +use, and other such housekeeping tasks. + +@item 2. Summary and Copyright +The @dfn{Summary and Copyright} segment describes the document and +contains the copyright notice and copying permissions. This is done +with the @code{@@copying} command. + +@item 3. Title and Copyright +The @dfn{Title and Copyright} segment contains the title and copyright +pages for the printed manual. The segment must be enclosed between +@code{@@titlepage} and @code{@@end titlepage} commands. The title and +copyright page appear only in the printed manual. + +@item 4. `Top' Node and Master Menu +The `Top' node starts off the online output; it does not appear in the +printed manual. We recommend including the copying permissions here as +well as the segments above. And it contains at least a top-level menu +listing the chapters, and possibly a @dfn{Master Menu} listing all the +nodes in the entire document. + +@item 5. Body +The @dfn{Body} of the document is typically structured like a +traditional book or encyclopedia, but it may be free form. + +@item 6. End +The @dfn{End} segment may contain commands for printing indices, and +closes with the @code{@@bye} command on a line of its own. +@end table + + +@node Short Sample +@section A Short Sample Texinfo File +@cindex Sample Texinfo file, with comments + +Here is a very short but complete Texinfo file, in the six conventional +parts enumerated in the previous section, so you can see how Texinfo +source appears in practice. The first three parts of the file, from +@samp{\input texinfo} through to @samp{@@end titlepage}, look more +intimidating than they are: most of the material is standard +boilerplate; when writing a manual, you simply change the names as +appropriate. + +@xref{Beginning a File}, for full documentation on the commands listed +here. @xref{GNU Sample Texts}, for the full texts to be used in GNU +manuals. + +In the following, the sample text is @emph{indented}; comments on it are +not. The complete file, without interspersed comments, is shown in +@ref{Short Sample Texinfo File}. + +@subheading Part 1: Header + +@noindent +The header does not appear in either the Info file or the +printed output. It sets various parameters, including the +name of the Info file and the title used in the header. + +@example +@group +\input texinfo @@c -*-texinfo-*- +@@c %**start of header +@@setfilename sample.info +@@settitle Sample Manual 1.0 +@@c %**end of header +@end group +@end example + +@subheading Part 2: Summary Description and Copyright + +@noindent +A real manual includes more text here, according to the license under +which it is distributed. @xref{GNU Sample Texts}. + +@example +@group +@@copying +This is a short example of a complete Texinfo file, version 1.0. + +Copyright @@copyright@{@} 2005 Free Software Foundation, Inc. +@@end copying +@end group +@end example + +@subheading Part 3: Titlepage, Contents, Copyright + +@noindent +The titlepage segment does not appear in the online output, only in the +printed manual. We use the @code{@@insertcopying} command to +include the permission text from the previous section, instead of +writing it out again; it is output on the back of the title page. The +@code{@@contents} command generates a table of contents. + +@example +@group +@@titlepage +@@title Sample Title +@end group + +@group +@@c The following two commands start the copyright page. +@@page +@@vskip 0pt plus 1filll +@@insertcopying +@@end titlepage +@end group + +@@c Output the table of contents at the beginning. +@@contents +@end example + +@subheading Part 4: `Top' Node and Master Menu + +@noindent +The `Top' node contains the master menu for the Info file. Since the +printed manual uses a table of contents rather than a menu, it +excludes the `Top' node. We repeat the short description from the +beginning of the @samp{@@copying} text, but there's no need to repeat +the copyright information, so we don't use @samp{@@insertcopying} here. +The @samp{@@top} command itself helps @command{makeinfo} determine the +relationships between nodes. + +@example +@@ifnottex +@@node Top +@@top Short Sample + +This is a short sample Texinfo file. +@@end ifnottex + +@group +@@menu +* First Chapter:: The first chapter is the + only chapter in this sample. +* Index:: Complete index. +@@end menu +@end group +@end example + + +@subheading Part 5: The Body of the Document + +@noindent +The body segment contains all the text of the document, but not the +indices or table of contents. This example illustrates a node and a +chapter containing an enumerated list. + +@example +@group +@@node First Chapter +@@chapter First Chapter + +@@cindex chapter, first +@end group + +@group +This is the first chapter. +@@cindex index entry, another +@end group + +@group +Here is a numbered list. + +@@enumerate +@@item +This is the first item. + +@@item +This is the second item. +@@end enumerate +@end group +@end example + + +@subheading Part 6: The End of the Document + +@noindent +The end segment contains commands for generating an index in a node and +unnumbered chapter of its own, and the @code{@@bye} command that marks +the end of the document. + +@example +@group +@@node Index +@@unnumbered Index +@end group + +@group +@@printindex cp + +@@bye +@end group +@end example + + +@subheading Some Results + +Here is what the contents of the first chapter of the sample look like: + +@sp 1 +@need 700 +@quotation +This is the first chapter. + +Here is a numbered list. + +@enumerate +@item +This is the first item. + +@item +This is the second item. +@end enumerate +@end quotation + + +@node History +@section History + +@cindex Stallman, Richard M. +@cindex Chassell, Robert J. +@cindex Fox, Brian +@cindex Berry, Karl +Richard M. Stallman invented the Texinfo format, wrote the initial +processors, and created Edition 1.0 of this manual. Robert@tie{}J. +Chassell greatly revised and extended the manual, starting with +Edition 1.1. Brian Fox was responsible for the standalone Texinfo +distribution until version 3.8, and wrote the standalone +@command{makeinfo} and @command{info} programs. Karl Berry has +continued maintenance since Texinfo 3.8 (manual edition 2.22). + +@cindex Pinard, Fran@,{c}ois +@cindex Zuhn, David D. +@cindex Weisshaus, Melissa +@cindex Zaretskii, Eli +@cindex Schwab, Andreas +@cindex Weinberg, Zack +Our thanks go out to all who helped improve this work, particularly the +indefatigable Eli Zaretskii and Andreas Schwab, who have provided +patches beyond counting. Fran@,{c}ois Pinard and David@tie{}D. Zuhn, +tirelessly recorded and reported mistakes and obscurities. Zack +Weinberg did the impossible by implementing the macro syntax in +@file{texinfo.tex}. Special thanks go to Melissa Weisshaus for her +frequent reviews of nearly similar editions. Dozens of others have +contributed patches and suggestions, they are gratefully acknowledged in +the @file{ChangeLog} file. Our mistakes are our own. + +@cindex Scribe +@cindex Reid, Brian +@cindex History of Texinfo +@cindex Texinfo history +A bit of history: in the 1970's at CMU, Brian Reid developed a program +and format named Scribe to mark up documents for printing. It used the +@code{@@} character to introduce commands, as Texinfo does. Much more +consequentially, it strove to describe document contents rather than +formatting, an idea wholeheartedly adopted by Texinfo. + +@cindex Bolio +@cindex Bo@TeX{} +Meanwhile, people at MIT developed another, not too dissimilar format +called Bolio. This then was converted to using @TeX{} as its typesetting +language: Bo@TeX{}. The earliest Bo@TeX{} version seems to have been +0.02 on October 31, 1984. + +Bo@TeX{} could only be used as a markup language for documents to be +printed, not for online documents. Richard Stallman (RMS) worked on +both Bolio and Bo@TeX{}. He also developed a nifty on-line help format +called Info, and then combined Bo@TeX{} and Info to create Texinfo, a +mark up language for text that is intended to be read both online and +as printed hard copy. + + +@node Texinfo Mode +@chapter Using Texinfo Mode +@cindex Texinfo mode +@cindex Mode, using Texinfo +@cindex GNU Emacs +@cindex Emacs + +You may edit a Texinfo file with any text editor you choose. A Texinfo +file is no different from any other ASCII file. However, GNU Emacs +comes with a special mode, called Texinfo mode, that provides Emacs +commands and tools to help ease your work. + +This chapter describes features of GNU Emacs' Texinfo mode but not any +features of the Texinfo formatting language. So if you are reading this +manual straight through from the beginning, you may want to skim through +this chapter briefly and come back to it after reading succeeding +chapters which describe the Texinfo formatting language in detail. + +@menu +* Texinfo Mode Overview:: How Texinfo mode can help you. +* Emacs Editing:: Texinfo mode adds to GNU Emacs' general + purpose editing features. +* Inserting:: How to insert frequently used @@-commands. +* Showing the Structure:: How to show the structure of a file. +* Updating Nodes and Menus:: How to update or create new nodes and menus. +* Info Formatting:: How to format for Info. +* Printing:: How to format and print part or all of a file. +* Texinfo Mode Summary:: Summary of all the Texinfo mode commands. +@end menu + +@node Texinfo Mode Overview +@section Texinfo Mode Overview + +Texinfo mode provides special features for working with Texinfo files. +You can: + +@itemize @bullet +@item +Insert frequently used @@-commands. @refill + +@item +Automatically create @code{@@node} lines. + +@item +Show the structure of a Texinfo source file.@refill + +@item +Automatically create or update the `Next', +`Previous', and `Up' pointers of a node. + +@item +Automatically create or update menus.@refill + +@item +Automatically create a master menu.@refill + +@item +Format a part or all of a file for Info.@refill + +@item +Typeset and print part or all of a file.@refill +@end itemize + +Perhaps the two most helpful features are those for inserting frequently +used @@-commands and for creating node pointers and menus.@refill + +@node Emacs Editing +@section The Usual GNU Emacs Editing Commands + +In most cases, the usual Text mode commands work the same in Texinfo +mode as they do in Text mode. Texinfo mode adds new editing commands +and tools to GNU Emacs' general purpose editing features. The major +difference concerns filling. In Texinfo mode, the paragraph +separation variable and syntax table are redefined so that Texinfo +commands that should be on lines of their own are not inadvertently +included in paragraphs. Thus, the @kbd{M-q} (@code{fill-paragraph}) +command will refill a paragraph but not mix an indexing command on a +line adjacent to it into the paragraph.@refill + +In addition, Texinfo mode sets the @code{page-delimiter} variable to +the value of @code{texinfo-chapter-level-regexp}; by default, this is +a regular expression matching the commands for chapters and their +equivalents, such as appendices. With this value for the page +delimiter, you can jump from chapter title to chapter title with the +@kbd{C-x ]} (@code{forward-page}) and @kbd{C-x [} +(@code{backward-page}) commands and narrow to a chapter with the +@kbd{C-x n p} (@code{narrow-to-page}) command. (@xref{Pages, , ,emacs, +The GNU Emacs Manual}, for details about the page commands.)@refill + +You may name a Texinfo file however you wish, but the convention is to +end a Texinfo file name with one of the extensions +@file{.texinfo}, @file{.texi}, @file{.txi}, or @file{.tex}. A longer +extension is preferred, since it is explicit, but a shorter extension +may be necessary for operating systems that limit the length of file +names. GNU Emacs automatically enters Texinfo mode when you visit a +file with a @file{.texinfo}, @file{.texi} or @file{.txi} +extension. Also, Emacs switches to Texinfo mode +when you visit a +file that has @samp{-*-texinfo-*-} in its first line. If ever you are +in another mode and wish to switch to Texinfo mode, type @code{M-x +texinfo-mode}.@refill + +Like all other Emacs features, you can customize or enhance Texinfo +mode as you wish. In particular, the keybindings are very easy to +change. The keybindings described here are the default or standard +ones.@refill + +@node Inserting +@comment node-name, next, previous, up +@section Inserting Frequently Used Commands +@cindex Inserting frequently used commands +@cindex Frequently used commands, inserting +@cindex Commands, inserting them + +Texinfo mode provides commands to insert various frequently used +@@-commands into the buffer. You can use these commands to save +keystrokes.@refill + +The insert commands are invoked by typing @kbd{C-c} twice and then the +first letter of the @@-command:@refill + +@table @kbd +@item C-c C-c c +@itemx M-x texinfo-insert-@@code +@findex texinfo-insert-@@code +Insert @code{@@code@{@}} and put the +cursor between the braces.@refill + +@item C-c C-c d +@itemx M-x texinfo-insert-@@dfn +@findex texinfo-insert-@@dfn +Insert @code{@@dfn@{@}} and put the +cursor between the braces.@refill + +@item C-c C-c e +@itemx M-x texinfo-insert-@@end +@findex texinfo-insert-@@end +Insert @code{@@end} and attempt to insert the correct following word, +such as @samp{example} or @samp{table}. (This command does not handle +nested lists correctly, but inserts the word appropriate to the +immediately preceding list.)@refill + +@item C-c C-c i +@itemx M-x texinfo-insert-@@item +@findex texinfo-insert-@@item +Insert @code{@@item} and put the +cursor at the beginning of the next line.@refill + +@item C-c C-c k +@itemx M-x texinfo-insert-@@kbd +@findex texinfo-insert-@@kbd +Insert @code{@@kbd@{@}} and put the +cursor between the braces.@refill + +@item C-c C-c n +@itemx M-x texinfo-insert-@@node +@findex texinfo-insert-@@node +Insert @code{@@node} and a comment line +listing the sequence for the `Next', +`Previous', and `Up' nodes. +Leave point after the @code{@@node}.@refill + +@item C-c C-c o +@itemx M-x texinfo-insert-@@noindent +@findex texinfo-insert-@@noindent +Insert @code{@@noindent} and put the +cursor at the beginning of the next line.@refill + +@item C-c C-c s +@itemx M-x texinfo-insert-@@samp +@findex texinfo-insert-@@samp +Insert @code{@@samp@{@}} and put the +cursor between the braces.@refill + +@item C-c C-c t +@itemx M-x texinfo-insert-@@table +@findex texinfo-insert-@@table +Insert @code{@@table} followed by a @key{SPC} +and leave the cursor after the @key{SPC}.@refill + +@item C-c C-c v +@itemx M-x texinfo-insert-@@var +@findex texinfo-insert-@@var +Insert @code{@@var@{@}} and put the +cursor between the braces.@refill + +@item C-c C-c x +@itemx M-x texinfo-insert-@@example +@findex texinfo-insert-@@example +Insert @code{@@example} and put the +cursor at the beginning of the next line.@refill + +@c M-@{ was the binding for texinfo-insert-braces; +@c in Emacs 19, backward-paragraph will take this binding. +@item C-c C-c @{ +@itemx M-x texinfo-insert-braces +@findex texinfo-insert-braces +Insert @code{@{@}} and put the cursor between the braces.@refill + +@item C-c @} +@itemx C-c ] +@itemx M-x up-list +@findex up-list +Move from between a pair of braces forward past the closing brace. +Typing @kbd{C-c ]} is easier than typing @kbd{C-c @}}, which +is, however, more mnemonic; hence the two keybindings. (Also, you can +move out from between braces by typing @kbd{C-f}.)@refill +@end table + +To put a command such as @w{@code{@@code@{@dots{}@}}} around an +@emph{existing} word, position the cursor in front of the word and type +@kbd{C-u 1 C-c C-c c}. This makes it easy to edit existing plain text. +The value of the prefix argument tells Emacs how many words following +point to include between braces---@samp{1} for one word, @samp{2} for +two words, and so on. Use a negative argument to enclose the previous +word or words. If you do not specify a prefix argument, Emacs inserts +the @@-command string and positions the cursor between the braces. This +feature works only for those @@-commands that operate on a word or words +within one line, such as @code{@@kbd} and @code{@@var}.@refill + +This set of insert commands was created after analyzing the frequency +with which different @@-commands are used in the @cite{GNU Emacs +Manual} and the @cite{GDB Manual}. If you wish to add your own insert +commands, you can bind a keyboard macro to a key, use abbreviations, +or extend the code in @file{texinfo.el}.@refill + +@findex texinfo-start-menu-description +@cindex Menu description, start +@cindex Description for menu, start +@kbd{C-c C-c C-d} (@code{texinfo-start-menu-description}) is an insert +command that works differently from the other insert commands. It +inserts a node's section or chapter title in the space for the +description in a menu entry line. (A menu entry has three parts, the +entry name, the node name, and the description. Only the node name is +required, but a description helps explain what the node is about. +@xref{Menu Parts, , The Parts of a Menu}.)@refill + +To use @code{texinfo-start-menu-description}, position point in a menu +entry line and type @kbd{C-c C-c C-d}. The command looks for and copies +the title that goes with the node name, and inserts the title as a +description; it positions point at beginning of the inserted text so you +can edit it. The function does not insert the title if the menu entry +line already contains a description.@refill + +This command is only an aid to writing descriptions; it does not do the +whole job. You must edit the inserted text since a title tends to use +the same words as a node name but a useful description uses different +words.@refill + +@node Showing the Structure +@comment node-name, next, previous, up +@section Showing the Section Structure of a File +@cindex Showing the section structure of a file +@cindex Section structure of a file, showing it +@cindex Structure of a file, showing it +@cindex Outline of file structure, showing it +@cindex Contents-like outline of file structure +@cindex File section structure, showing it +@cindex Texinfo file section structure, showing it + +You can show the section structure of a Texinfo file by using the +@kbd{C-c C-s} command (@code{texinfo-show-structure}). This command +shows the section structure of a Texinfo file by listing the lines +that begin with the @@-commands for @code{@@chapter}, +@code{@@section}, and the like. It constructs what amounts +to a table of contents. These lines are displayed in another buffer +called the @samp{*Occur*} buffer. In that buffer, you can position +the cursor over one of the lines and use the @kbd{C-c C-c} command +(@code{occur-mode-goto-occurrence}), to jump to the corresponding spot +in the Texinfo file.@refill + +@table @kbd +@item C-c C-s +@itemx M-x texinfo-show-structure +@findex texinfo-show-structure +Show the @code{@@chapter}, @code{@@section}, and such lines of a +Texinfo file.@refill + +@item C-c C-c +@itemx M-x occur-mode-goto-occurrence +@findex occur-mode-goto-occurrence +Go to the line in the Texinfo file corresponding to the line under the +cursor in the @file{*Occur*} buffer.@refill +@end table + +If you call @code{texinfo-show-structure} with a prefix argument by +typing @w{@kbd{C-u C-c C-s}}, it will list not only those lines with the +@@-commands for @code{@@chapter}, @code{@@section}, and the like, but +also the @code{@@node} lines. You can use @code{texinfo-show-structure} +with a prefix argument to check whether the `Next', `Previous', and `Up' +pointers of an @code{@@node} line are correct. + +Often, when you are working on a manual, you will be interested only +in the structure of the current chapter. In this case, you can mark +off the region of the buffer that you are interested in by using the +@kbd{C-x n n} (@code{narrow-to-region}) command and +@code{texinfo-show-structure} will work on only that region. To see +the whole buffer again, use @w{@kbd{C-x n w}} (@code{widen}). +(@xref{Narrowing, , , emacs, The GNU Emacs Manual}, for more +information about the narrowing commands.)@refill + +@vindex page-delimiter +@cindex Page delimiter in Texinfo mode +In addition to providing the @code{texinfo-show-structure} command, +Texinfo mode sets the value of the page delimiter variable to match +the chapter-level @@-commands. This enables you to use the @kbd{C-x +]} (@code{forward-page}) and @kbd{C-x [} (@code{backward-page}) +commands to move forward and backward by chapter, and to use the +@kbd{C-x n p} (@code{narrow-to-page}) command to narrow to a chapter. +@xref{Pages, , , emacs, The GNU Emacs Manual}, for more information +about the page commands.@refill + +@node Updating Nodes and Menus +@comment node-name, next, previous, up +@section Updating Nodes and Menus +@cindex Updating nodes and menus +@cindex Create nodes, menus automatically +@cindex Insert nodes, menus automatically +@cindex Automatically insert nodes, menus + +Texinfo mode provides commands for automatically creating or updating +menus and node pointers. The commands are called ``update'' commands +because their most frequent use is for updating a Texinfo file after you +have worked on it; but you can use them to insert the `Next', +`Previous', and `Up' pointers into an @code{@@node} line that has none +and to create menus in a file that has none. + +If you do not use the updating commands, you need to write menus and +node pointers by hand, which is a tedious task.@refill + +@menu +* Updating Commands:: Five major updating commands. +* Updating Requirements:: How to structure a Texinfo file for + using the updating command. +* Other Updating Commands:: How to indent descriptions, insert + missing nodes lines, and update + nodes in sequence. +@end menu + +@node Updating Commands +@subsection The Updating Commands + +You can use the updating commands to:@refill + +@itemize @bullet +@item +insert or update the `Next', `Previous', and `Up' pointers of a +node,@refill + +@item +insert or update the menu for a section, and@refill + +@item +create a master menu for a Texinfo source file.@refill +@end itemize + +You can also use the commands to update all the nodes and menus in a +region or in a whole Texinfo file.@refill + +The updating commands work only with conventional Texinfo files, which +are structured hierarchically like books. In such files, a structuring +command line must follow closely after each @code{@@node} line, except +for the `Top' @code{@@node} line. (A @dfn{structuring command line} is +a line beginning with @code{@@chapter}, @code{@@section}, or other +similar command.) + +You can write the structuring command line on the line that follows +immediately after an @code{@@node} line or else on the line that +follows after a single @code{@@comment} line or a single +@code{@@ifinfo} line. You cannot interpose more than one line between +the @code{@@node} line and the structuring command line; and you may +interpose only an @code{@@comment} line or an @code{@@ifinfo} line. + +Commands which work on a whole buffer require that the `Top' node be +followed by a node with an @code{@@chapter} or equivalent-level command. +The menu updating commands will not create a main or master menu for a +Texinfo file that has only @code{@@chapter}-level nodes! The menu +updating commands only create menus @emph{within} nodes for lower level +nodes. To create a menu of chapters, you must provide a `Top' +node. + +The menu updating commands remove menu entries that refer to other Info +files since they do not refer to nodes within the current buffer. This +is a deficiency. Rather than use menu entries, you can use cross +references to refer to other Info files. None of the updating commands +affect cross references.@refill + +Texinfo mode has five updating commands that are used most often: two +are for updating the node pointers or menu of a single node (or a +region); two are for updating every node pointer and menu in a file; +and one, the @code{texinfo-master-menu} command, is for creating a +master menu for a complete file, and optionally, for updating every +node and menu in the whole Texinfo file.@refill + +The @code{texinfo-master-menu} command is the primary command:@refill + +@table @kbd +@item C-c C-u m +@itemx M-x texinfo-master-menu +@findex texinfo-master-menu +Create or update a master menu that includes all the other menus +(incorporating the descriptions from pre-existing menus, if +any).@refill + +With an argument (prefix argument, @kbd{C-u,} if interactive), first create or +update all the nodes and all the regular menus in the buffer before +constructing the master menu. (@xref{The Top Node, , The Top Node and +Master Menu}, for more about a master menu.)@refill + +For @code{texinfo-master-menu} to work, the Texinfo file must have a +`Top' node and at least one subsequent node.@refill + +After extensively editing a Texinfo file, you can type the following: + +@example +C-u M-x texinfo-master-menu +@exdent or +C-u C-c C-u m +@end example + +@noindent +This updates all the nodes and menus completely and all at once.@refill +@end table + +The other major updating commands do smaller jobs and are designed for +the person who updates nodes and menus as he or she writes a Texinfo +file.@refill + +@need 1000 +The commands are:@refill + +@table @kbd +@item C-c C-u C-n +@itemx M-x texinfo-update-node +@findex texinfo-update-node +Insert the `Next', `Previous', and `Up' pointers for the node that point is +within (i.e., for the @code{@@node} line preceding point). If the +@code{@@node} line has pre-existing `Next', `Previous', or `Up' +pointers in it, the old pointers are removed and new ones inserted. +With an argument (prefix argument, @kbd{C-u}, if interactive), this command +updates all @code{@@node} lines in the region (which is the text +between point and mark).@refill + +@item C-c C-u C-m +@itemx M-x texinfo-make-menu +@findex texinfo-make-menu +Create or update the menu in the node that point is within. +With an argument (@kbd{C-u} as prefix argument, if +interactive), the command makes or updates menus for the +nodes which are either within or a part of the +region.@refill + +Whenever @code{texinfo-make-menu} updates an existing menu, the +descriptions from that menu are incorporated into the new menu. This +is done by copying descriptions from the existing menu to the entries +in the new menu that have the same node names. If the node names are +different, the descriptions are not copied to the new menu.@refill + +@item C-c C-u C-e +@itemx M-x texinfo-every-node-update +@findex texinfo-every-node-update +Insert or update the `Next', `Previous', and `Up' pointers for every +node in the buffer.@refill + +@item C-c C-u C-a +@itemx M-x texinfo-all-menus-update +@findex texinfo-all-menus-update +Create or update all the menus in the buffer. With an argument +(@kbd{C-u} as prefix argument, if interactive), first insert +or update all the node +pointers before working on the menus.@refill + +If a master menu exists, the @code{texinfo-all-menus-update} command +updates it; but the command does not create a new master menu if none +already exists. (Use the @code{texinfo-master-menu} command for +that.)@refill + +When working on a document that does not merit a master menu, you can +type the following: + +@example +C-u C-c C-u C-a +@exdent or +C-u M-x texinfo-all-menus-update +@end example + +@noindent +This updates all the nodes and menus.@refill +@end table + +The @code{texinfo-column-for-description} variable specifies the +column to which menu descriptions are indented. By default, the value +is 32 although it can be useful to reduce it to as low as 24. You +can set the variable via customization (@pxref{Changing an Option,,, +emacs, The GNU Emacs Manual}) or with the @kbd{M-x set-variable} +command (@pxref{Examining, , Examining and Setting Variables, emacs, +The GNU Emacs Manual}). + +Also, the @code{texinfo-indent-menu-description} command may be used to +indent existing menu descriptions to a specified column. Finally, if +you wish, you can use the @code{texinfo-insert-node-lines} command to +insert missing @code{@@node} lines into a file. (@xref{Other Updating +Commands}, for more information.)@refill + +@node Updating Requirements +@subsection Updating Requirements +@cindex Updating requirements +@cindex Requirements for updating commands + +To use the updating commands, you must organize the Texinfo file +hierarchically with chapters, sections, subsections, and the like. +When you construct the hierarchy of the manual, do not `jump down' +more than one level at a time: you can follow the `Top' node with a +chapter, but not with a section; you can follow a chapter with a +section, but not with a subsection. However, you may `jump up' any +number of levels at one time---for example, from a subsection to a +chapter.@refill + +Each @code{@@node} line, with the exception of the line for the `Top' +node, must be followed by a line with a structuring command such as +@code{@@chapter}, @code{@@section}, or +@code{@@unnumberedsubsec}.@refill + +Each @code{@@node} line/structuring-command line combination +must look either like this: + +@example +@group +@@node Comments, Minimum, Conventions, Overview +@@comment node-name, next, previous, up +@@section Comments +@end group +@end example + +or like this (without the @code{@@comment} line): + +@example +@group +@@node Comments, Minimum, Conventions, Overview +@@section Comments +@end group +@end example + +or like this (without the explicit node pointers): + +@example +@group +@@node Comments +@@section Comments +@end group +@end example + +@noindent +In this example, `Comments' is the name of both the node and the +section. The next node is called `Minimum' and the previous node is +called `Conventions'. The `Comments' section is within the `Overview' +node, which is specified by the `Up' pointer. (Instead of an +@code{@@comment} line, you may also write an @code{@@ifinfo} line.) + +If a file has a `Top' node, it must be called @samp{top} or @samp{Top} +and be the first node in the file. + +The menu updating commands create a menu of sections within a chapter, +a menu of subsections within a section, and so on. This means that +you must have a `Top' node if you want a menu of chapters.@refill + +Incidentally, the @code{makeinfo} command will create an Info file for a +hierarchically organized Texinfo file that lacks `Next', `Previous' and +`Up' pointers. Thus, if you can be sure that your Texinfo file will be +formatted with @code{makeinfo}, you have no need for the update node +commands. (@xref{Creating an Info File}, for more information about +@code{makeinfo}.) However, both @code{makeinfo} and the +@code{texinfo-format-@dots{}} commands require that you insert menus in +the file. + + +@node Other Updating Commands +@subsection Other Updating Commands + +In addition to the five major updating commands, Texinfo mode +possesses several less frequently used updating commands:@refill + +@table @kbd +@item M-x texinfo-insert-node-lines +@findex texinfo-insert-node-lines +Insert @code{@@node} lines before the @code{@@chapter}, +@code{@@section}, and other sectioning commands wherever they are +missing throughout a region in a Texinfo file.@refill + +With an argument (@kbd{C-u} as prefix argument, if interactive), the +@code{texinfo-insert-node-lines} command not only inserts +@code{@@node} lines but also inserts the chapter or section titles as +the names of the corresponding nodes. In addition, it inserts the +titles as node names in pre-existing @code{@@node} lines that lack +names. Since node names should be more concise than section or +chapter titles, you must manually edit node names so inserted.@refill + +For example, the following marks a whole buffer as a region and inserts +@code{@@node} lines and titles throughout:@refill + +@example +C-x h C-u M-x texinfo-insert-node-lines +@end example + +This command inserts titles as node names in @code{@@node} lines; the +@code{texinfo-start-menu-description} command (@pxref{Inserting, +Inserting Frequently Used Commands}) inserts titles as descriptions in +menu entries, a different action. However, in both cases, you need to +edit the inserted text. + +@item M-x texinfo-multiple-files-update +@findex texinfo-multiple-files-update @r{(in brief)} +Update nodes and menus in a document built from several separate files. +With @kbd{C-u} as a prefix argument, create and insert a master menu in +the outer file. With a numeric prefix argument, such as @kbd{C-u 2}, first +update all the menus and all the `Next', `Previous', and `Up' pointers +of all the included files before creating and inserting a master menu in +the outer file. The @code{texinfo-multiple-files-update} command is +described in the appendix on @code{@@include} files. +@xref{texinfo-multiple-files-update}. + +@item M-x texinfo-indent-menu-description +@findex texinfo-indent-menu-description +Indent every description in the menu following point to the specified +column. You can use this command to give yourself more space for +descriptions. With an argument (@kbd{C-u} as prefix argument, if +interactive), the @code{texinfo-indent-menu-description} command indents +every description in every menu in the region. However, this command +does not indent the second and subsequent lines of a multi-line +description.@refill + +@item M-x texinfo-sequential-node-update +@findex texinfo-sequential-node-update +Insert the names of the nodes immediately following and preceding the +current node as the `Next' or `Previous' pointers regardless of those +nodes' hierarchical level. This means that the `Next' node of a +subsection may well be the next chapter. Sequentially ordered nodes are +useful for novels and other documents that you read through +sequentially. (However, in Info, the @kbd{g *} command lets +you look through the file sequentially, so sequentially ordered nodes +are not strictly necessary.) With an argument (prefix argument, if +interactive), the @code{texinfo-sequential-node-update} command +sequentially updates all the nodes in the region.@refill +@end table + +@node Info Formatting +@comment node-name, next, previous, up +@section Formatting for Info +@cindex Formatting for Info +@cindex Running an Info formatter +@cindex Info formatting + +Texinfo mode provides several commands for formatting part or all of a +Texinfo file for Info. Often, when you are writing a document, you +want to format only part of a file---that is, a region.@refill + +You can use either the @code{texinfo-format-region} or the +@code{makeinfo-region} command to format a region:@refill + +@table @kbd +@findex texinfo-format-region +@item C-c C-e C-r +@itemx M-x texinfo-format-region +@itemx C-c C-m C-r +@itemx M-x makeinfo-region +Format the current region for Info.@refill +@end table + +You can use either the @code{texinfo-format-buffer} or the +@code{makeinfo-buffer} command to format a whole buffer:@refill + +@table @kbd +@findex texinfo-format-buffer +@item C-c C-e C-b +@itemx M-x texinfo-format-buffer +@itemx C-c C-m C-b +@itemx M-x makeinfo-buffer +Format the current buffer for Info.@refill +@end table + +@need 1000 +For example, after writing a Texinfo file, you can type the following: + +@example +C-u C-c C-u m +@exdent or +C-u M-x texinfo-master-menu +@end example + +@noindent +This updates all the nodes and menus. Then type the following to create +an Info file: + +@example +C-c C-m C-b +@exdent or +M-x makeinfo-buffer +@end example + +For @TeX{} or the Info formatting commands to work, the file @emph{must} +include a line that has @code{@@setfilename} in its header. + +@xref{Creating an Info File}, for details about Info formatting.@refill + +@node Printing +@comment node-name, next, previous, up +@section Printing +@cindex Formatting for printing +@cindex Printing a region or buffer +@cindex Region formatting and printing +@cindex Buffer formatting and printing +@cindex Part of file formatting and printing + +Typesetting and printing a Texinfo file is a multi-step process in which +you first create a file for printing (called a DVI file), and then +print the file. Optionally, you may also create indices. To do this, +you must run the @code{texindex} command after first running the +@code{tex} typesetting command; and then you must run the @code{tex} +command again. Or else run the @code{texi2dvi} command which +automatically creates indices as needed (@pxref{Format with texi2dvi}). + +Often, when you are writing a document, you want to typeset and print +only part of a file to see what it will look like. You can use the +@code{texinfo-tex-region} and related commands for this purpose. Use +the @code{texinfo-tex-buffer} command to format all of a +buffer.@refill + +@table @kbd +@item C-c C-t C-b +@itemx M-x texinfo-tex-buffer +@findex texinfo-tex-buffer +Run @code{texi2dvi} on the buffer. In addition to running @TeX{} on the +buffer, this command automatically creates or updates indices as +needed.@refill + +@item C-c C-t C-r +@itemx M-x texinfo-tex-region +@findex texinfo-tex-region +Run @TeX{} on the region.@refill + +@item C-c C-t C-i +@itemx M-x texinfo-texindex +Run @code{texindex} to sort the indices of a Texinfo file formatted with +@code{texinfo-tex-region}. The @code{texinfo-tex-region} command does +not run @code{texindex} automatically; it only runs the @code{tex} +typesetting command. You must run the @code{texinfo-tex-region} command +a second time after sorting the raw index files with the @code{texindex} +command. (Usually, you do not format an index when you format a region, +only when you format a buffer. Now that the @code{texi2dvi} command +exists, there is little or no need for this command.)@refill + +@item C-c C-t C-p +@itemx M-x texinfo-tex-print +@findex texinfo-tex-print +Print the file (or the part of the file) previously formatted with +@code{texinfo-tex-buffer} or @code{texinfo-tex-region}.@refill +@end table + +For @code{texinfo-tex-region} or @code{texinfo-tex-buffer} to work, the +file @emph{must} start with a @samp{\input texinfo} line and must +include an @code{@@settitle} line. The file must end with @code{@@bye} +on a line by itself. (When you use @code{texinfo-tex-region}, you must +surround the @code{@@settitle} line with start-of-header and +end-of-header lines.)@refill + +@xref{Hardcopy}, for a description of the other @TeX{} related +commands, such as @code{tex-show-print-queue}.@refill + +@node Texinfo Mode Summary +@comment node-name, next, previous, up +@section Texinfo Mode Summary + +In Texinfo mode, each set of commands has default keybindings that +begin with the same keys. All the commands that are custom-created +for Texinfo mode begin with @kbd{C-c}. The keys are somewhat +mnemonic.@refill + +@subheading Insert Commands + +The insert commands are invoked by typing @kbd{C-c} twice and then the +first letter of the @@-command to be inserted. (It might make more +sense mnemonically to use @kbd{C-c C-i}, for `custom insert', but +@kbd{C-c C-c} is quick to type.)@refill + +@example +C-c C-c c @r{Insert} @samp{@@code}. +C-c C-c d @r{Insert} @samp{@@dfn}. +C-c C-c e @r{Insert} @samp{@@end}. +C-c C-c i @r{Insert} @samp{@@item}. +C-c C-c n @r{Insert} @samp{@@node}. +C-c C-c s @r{Insert} @samp{@@samp}. +C-c C-c v @r{Insert} @samp{@@var}. +C-c @{ @r{Insert braces.} +C-c ] +C-c @} @r{Move out of enclosing braces.} + +@group +C-c C-c C-d @r{Insert a node's section title} + @r{in the space for the description} + @r{in a menu entry line.} +@end group +@end example + +@subheading Show Structure + +The @code{texinfo-show-structure} command is often used within a +narrowed region.@refill + +@example +C-c C-s @r{List all the headings.} +@end example + +@subheading The Master Update Command + +The @code{texinfo-master-menu} command creates a master menu; and can +be used to update every node and menu in a file as well.@refill + +@c Probably should use @tables in this section. +@example +@group +C-c C-u m +M-x texinfo-master-menu + @r{Create or update a master menu.} +@end group + +@group +C-u C-c C-u m @r{With @kbd{C-u} as a prefix argument, first} + @r{create or update all nodes and regular} + @r{menus, and then create a master menu.} +@end group +@end example + +@subheading Update Pointers + +The update pointer commands are invoked by typing @kbd{C-c C-u} and +then either @kbd{C-n} for @code{texinfo-update-node} or @kbd{C-e} for +@code{texinfo-every-node-update}.@refill + +@example +C-c C-u C-n @r{Update a node.} +C-c C-u C-e @r{Update every node in the buffer.} +@end example + +@subheading Update Menus + +Invoke the update menu commands by typing @kbd{C-c C-u} +and then either @kbd{C-m} for @code{texinfo-make-menu} or +@kbd{C-a} for @code{texinfo-all-menus-update}. To update +both nodes and menus at the same time, precede @kbd{C-c C-u +C-a} with @kbd{C-u}.@refill + +@example +C-c C-u C-m @r{Make or update a menu.} + +@group +C-c C-u C-a @r{Make or update all} + @r{menus in a buffer.} +@end group + +@group +C-u C-c C-u C-a @r{With @kbd{C-u} as a prefix argument,} + @r{first create or update all nodes and} + @r{then create or update all menus.} +@end group +@end example + +@subheading Format for Info + +The Info formatting commands that are written in Emacs Lisp are +invoked by typing @kbd{C-c C-e} and then either @kbd{C-r} for a region +or @kbd{C-b} for the whole buffer.@refill + +The Info formatting commands that are written in C and based on the +@code{makeinfo} program are invoked by typing @kbd{C-c C-m} and then +either @kbd{C-r} for a region or @kbd{C-b} for the whole buffer.@refill + +@need 800 +@noindent +Use the @code{texinfo-format@dots{}} commands: + +@example +@group +C-c C-e C-r @r{Format the region.} +C-c C-e C-b @r{Format the buffer.} +@end group +@end example + +@need 750 +@noindent +Use @code{makeinfo}: + +@example +C-c C-m C-r @r{Format the region.} +C-c C-m C-b @r{Format the buffer.} +C-c C-m C-l @r{Recenter the @code{makeinfo} output buffer.} +C-c C-m C-k @r{Kill the @code{makeinfo} formatting job.} +@end example + +@subheading Typeset and Print + +The @TeX{} typesetting and printing commands are invoked by typing +@kbd{C-c C-t} and then another control command: @kbd{C-r} for +@code{texinfo-tex-region}, @kbd{C-b} for @code{texinfo-tex-buffer}, +and so on.@refill + +@example +C-c C-t C-r @r{Run @TeX{} on the region.} +C-c C-t C-b @r{Run} @code{texi2dvi} @r{on the buffer.} +C-c C-t C-i @r{Run} @code{texindex}. +C-c C-t C-p @r{Print the DVI file.} +C-c C-t C-q @r{Show the print queue.} +C-c C-t C-d @r{Delete a job from the print queue.} +C-c C-t C-k @r{Kill the current @TeX{} formatting job.} +C-c C-t C-x @r{Quit a currently stopped @TeX{} formatting job.} +C-c C-t C-l @r{Recenter the output buffer.} +@end example + +@subheading Other Updating Commands + +The remaining updating commands do not have standard keybindings because +they are rarely used. + +@example +@group +M-x texinfo-insert-node-lines + @r{Insert missing @code{@@node} lines in region.} + @r{With @kbd{C-u} as a prefix argument,} + @r{use section titles as node names.} +@end group + +@group +M-x texinfo-multiple-files-update + @r{Update a multi-file document.} + @r{With @kbd{C-u 2} as a prefix argument,} + @r{create or update all nodes and menus} + @r{in all included files first.} +@end group + +@group +M-x texinfo-indent-menu-description + @r{Indent descriptions.} +@end group + +@group +M-x texinfo-sequential-node-update + @r{Insert node pointers in strict sequence.} +@end group +@end example + + +@node Beginning a File +@chapter Beginning a Texinfo File +@cindex Beginning a Texinfo file +@cindex Texinfo file beginning +@cindex File beginning + +Certain pieces of information must be provided at the beginning of a +Texinfo file, such as the name for the output file(s), the title of the +document, and the Top node. A table of contents is also generally +produced here. + +This chapter expands on the minimal complete Texinfo source file +previously given (@pxref{Six Parts}). It describes the numerous +commands for handling the traditional frontmatter items in Texinfo. + +@cindex Frontmatter, text in +Straight text outside of any command before the Top node should be +avoided. Such text is treated differently in the different output +formats: visible in @TeX{} and HTML, by default not shown in Info +readers, and so on. + +@menu +* Sample Beginning:: A sample beginning for a Texinfo file. +* Texinfo File Header:: The first lines. +* Document Permissions:: Ensuring your manual is free. +* Titlepage & Copyright Page:: Creating the title and copyright pages. +* Contents:: How to create a table of contents. +* The Top Node:: Creating the `Top' node and master menu. +* Global Document Commands:: Affecting formatting throughout. +* Software Copying Permissions:: Ensure that you and others continue to + have the right to use and share software. +@end menu + + +@node Sample Beginning +@section Sample Texinfo File Beginning + +@cindex Example beginning of Texinfo file + +The following sample shows what is needed. The elements given here are +explained in more detail in the following sections. Other commands are +often included at the beginning of Texinfo files, but the ones here are +the most critical. + +@xref{GNU Sample Texts}, for the full texts to be used in GNU manuals. + +@example +\input texinfo @@c -*-texinfo-*- +@@c %**start of header +@@setfilename @var{infoname}.info +@@settitle @var{name-of-manual} @var{version} +@@c %**end of header + +@@copying +This manual is for @var{program}, version @var{version}. + +Copyright @@copyright@{@} @var{years} @var{copyright-owner}. + +@group +@@quotation +Permission is granted to @dots{} +@@end quotation +@@end copying +@end group + +@group +@@titlepage +@@title @var{name-of-manual-when-printed} +@@subtitle @var{subtitle-if-any} +@@subtitle @var{second-subtitle} +@@author @var{author} +@end group + +@group +@@c The following two commands +@@c start the copyright page. +@@page +@@vskip 0pt plus 1filll +@@insertcopying +@end group + +Published by @dots{} +@@end titlepage + +@@c So the toc is printed at the start. +@@contents + +@@ifnottex +@@node Top +@@top @var{title} + +This manual is for @var{program}, version @var{version}. +@@end ifnottex + +@group +@@menu +* First Chapter:: Getting started @dots{} +* Second Chapter:: @dots{} + @dots{} +* Copying:: Your rights and freedoms. +@@end menu +@end group + +@group +@@node First Chapter +@@chapter First Chapter + +@@cindex first chapter +@@cindex chapter, first +@dots{} +@end group +@end example + + +@node Texinfo File Header +@section Texinfo File Header +@cindex Header for Texinfo files +@cindex Texinfo file header + +Texinfo files start with at least three lines that provide Info and +@TeX{} with necessary information. These are the @code{\input texinfo} +line, the @code{@@settitle} line, and the @code{@@setfilename} line. + +Also, if you want to format just part of the Texinfo file, you must +write the @code{@@settitle} and @code{@@setfilename} lines between +start-of-header and end-of-header lines. The start- and end-of-header +lines are optional, but they do no harm, so you might as well always +include them. + +Any command that affects document formatting as a whole makes sense to +include in the header. @code{@@synindex} (@pxref{synindex}), for +instance, is another command often included in the header. @xref{GNU +Sample Texts}, for complete sample texts. + +Thus, the beginning of a Texinfo file generally looks like this: + +@example +@group +\input texinfo @@c -*-texinfo-*- +@@c %**start of header +@@setfilename sample.info +@@settitle Sample Manual 1.0 +@@c %**end of header +@end group +@end example + +@menu +* First Line:: The first line of a Texinfo file. +* Start of Header:: Formatting a region requires this. +* setfilename:: Tell Info the name of the Info file. +* settitle:: Create a title for the printed work. +* End of Header:: Formatting a region requires this. +@end menu + + +@node First Line +@subsection The First Line of a Texinfo File +@cindex First line of a Texinfo file +@cindex Beginning line of a Texinfo file +@cindex Header of a Texinfo file + +Every Texinfo file that is to be the top-level input to @TeX{} must begin +with a line that looks like this: + +@example +\input texinfo @@c -*-texinfo-*- +@end example + +@noindent +This line serves two functions: + +@enumerate +@item +When the file is processed by @TeX{}, the @samp{\input texinfo} command +tells @TeX{} to load the macros needed for processing a Texinfo file. +These are in a file called @file{texinfo.tex}, which should have been +installed on your system along with either the @TeX{} or Texinfo +software. @TeX{} uses the backslash, @samp{\}, to mark the beginning of +a command, exactly as Texinfo uses @samp{@@}. The @file{texinfo.tex} +file causes the switch from @samp{\} to @samp{@@}; before the switch +occurs, @TeX{} requires @samp{\}, which is why it appears at the +beginning of the file. + +@item +When the file is edited in GNU Emacs, the @samp{-*-texinfo-*-} mode +specification tells Emacs to use Texinfo mode. +@end enumerate + + +@node Start of Header +@subsection Start of Header +@cindex Start of header line + +A start-of-header line is a Texinfo comment that looks like this: + +@example +@@c %**start of header +@end example + +Write the start-of-header line on the second line of a Texinfo file. +Follow the start-of-header line with @code{@@setfilename} and +@code{@@settitle} lines and, optionally, with other commands that +globally affect the document formatting, such as @code{@@synindex} or +@code{@@footnotestyle}; and then by an end-of-header line (@pxref{End of +Header}). + +The start- and end-of-header lines allow you to format only part of a +Texinfo file for Info or printing. @xref{texinfo-format commands}. + +The odd string of characters, @samp{%**}, is to ensure that no other +comment is accidentally taken for a start-of-header line. You can +change it if you wish by setting the @code{tex-start-of-header} and/or +@code{tex-end-of-header} Emacs variables. @xref{Texinfo Mode Printing}. + + +@node setfilename +@subsection @code{@@setfilename}: Set the output file name +@findex setfilename +@cindex Texinfo requires @code{@@setfilename} + +In order to serve as the primary input file for either @code{makeinfo} +or @TeX{}, a Texinfo file must contain a line that looks like this: + +@example +@@setfilename @var{info-file-name} +@end example + +Write the @code{@@setfilename} command at the beginning of a line and +follow it on the same line by the Info file name. Do not write anything +else on the line; anything on the line after the command is considered +part of the file name, including what would otherwise be a +comment. + +@cindex Ignored before @code{@@setfilename} +@cindex @samp{\input} source line ignored +The Info formatting commands ignore everything written before the +@code{@@setfilename} line, which is why the very first line of +the file (the @code{\input} line) does not show up in the output. + +The @code{@@setfilename} line specifies the name of the output file to +be generated. This name must be different from the name of the Texinfo +file. There are two conventions for choosing the name: you can either +remove the extension (such as @samp{.texi}) entirely from the input file +name, or, preferably, replace it with the @samp{.info} extension. + +@cindex Length of file names +@cindex File name collision +@cindex Info file name, choosing +Although an explicit @samp{.info} extension is preferable, some +operating systems cannot handle long file names. You can run into a +problem even when the file name you specify is itself short enough. +This occurs because the Info formatters split a long Info file into +short indirect subfiles, and name them by appending @samp{-1}, +@samp{-2}, @dots{}, @samp{-10}, @samp{-11}, and so on, to the original +file name. (@xref{Tag and Split Files}.) The subfile name +@file{texinfo.info-10}, for example, is too long for old systems with a +14-character limit on filenames; so the Info file name for this document +is @file{texinfo} rather than @file{texinfo.info}. When @code{makeinfo} +is running on operating systems such as MS-DOS which impose severe +limits on file names, it may remove some characters from the original +file name to leave enough space for the subfile suffix, thus producing +files named @file{texin-10}, @file{gcc.i12}, etc. + +When producing HTML output, @code{makeinfo} will replace any extension +with @samp{html}, or add @samp{.html} if the given name has no +extension. + +@pindex texinfo.cnf +The @code{@@setfilename} line produces no output when you typeset a +manual with @TeX{}, but it is nevertheless essential: it opens the +index, cross-reference, and other auxiliary files used by Texinfo, and +also reads @file{texinfo.cnf} if that file is present on your system +(@pxref{Preparing for TeX,, Preparing for @TeX{}}). + + +@node settitle +@subsection @code{@@settitle}: Set the document title +@findex settitle + +In order to be made into a printed manual, a Texinfo file must contain +a line that looks like this: + +@example +@@settitle @var{title} +@end example + +Write the @code{@@settitle} command at the beginning of a line and +follow it on the same line by the title. This tells @TeX{} the title to +use in a header or footer. Do not write anything else on the line; +anything on the line after the command is considered part of the title, +including what would otherwise be a comment. + +The @code{@@settitle} command should precede everything that generates +actual output. The best place for it is right after the +@code{@@setfilename} command (see the previous section). + +@cindex <title> HTML tag +In the HTML file produced by @command{makeinfo}, @var{title} serves as +the document @samp{<title>}. It also becomes the default document +description in the @samp{<head>} part (@pxref{documentdescription}). + +The title in the @code{@@settitle} command does not affect the title as +it appears on the title page. Thus, the two do not need not match +exactly. A practice we recommend is to include the version or edition +number of the manual in the @code{@@settitle} title; on the title page, +the version number generally appears as a @code{@@subtitle} so it would +be omitted from the @code{@@title}. @xref{titlepage}. + +Conventionally, when @TeX{} formats a Texinfo file for double-sided +output, the title is printed in the left-hand (even-numbered) page +headings and the current chapter title is printed in the right-hand +(odd-numbered) page headings. (@TeX{} learns the title of each chapter +from each @code{@@chapter} command.) By default, no page footer is +printed. + +Even if you are printing in a single-sided style, @TeX{} looks for an +@code{@@settitle} command line, in case you include the manual title +in the heading. + +@TeX{} prints page headings only for that text that comes after the +@code{@@end titlepage} command in the Texinfo file, or that comes +after an @code{@@headings} command that turns on headings. +(@xref{headings on off, , The @code{@@headings} Command}, for more +information.) + +You may, if you wish, create your own, customized headings and footings. +@xref{Headings}, for a detailed discussion of this. + + +@node End of Header +@subsection End of Header +@cindex End of header line + +Follow the header lines with an @w{end-of-header} line, which is a +Texinfo comment that looks like this: + +@example +@@c %**end of header +@end example + +@xref{Start of Header}. + + +@node Document Permissions +@section Document Permissions +@cindex Document Permissions +@cindex Copying Permissions + +The copyright notice and copying permissions for a document need to +appear in several places in the various Texinfo output formats. +Therefore, Texinfo provides a command (@code{@@copying}) to declare +this text once, and another command (@code{@@insertcopying}) to +insert the text at appropriate points. + +@menu +* copying:: Declare the document's copying permissions. +* insertcopying:: Where to insert the permissions. +@end menu + + +@node copying +@subsection @code{@@copying}: Declare Copying Permissions +@findex copying + +The @code{@@copying} command should be given very early in the document; +the recommended location is right after the header material +(@pxref{Texinfo File Header}). It conventionally consists of a sentence +or two about what the program is, identification of the documentation +itself, the legal copyright line, and the copying permissions. Here is +a skeletal example: + +@example +@@copying +This manual is for @var{program} (version @var{version}, updated +@var{date}), which @dots{} + +Copyright @@copyright@{@} @var{years} @var{copyright-owner}. + +@@quotation +Permission is granted to @dots{} +@@end quotation +@@end copying +@end example + +The @code{@@quotation} has no legal significance; it's there to improve +readability in some contexts. + +@xref{GNU Sample Texts}, for the full text to be used in GNU manuals. +@xref{GNU Free Documentation License}, for the license itself under +which GNU and other free manuals are distributed. You need to include +the license as an appendix to your document. + +The text of @code{@@copying} is output as a comment at the beginning of +Info, HTML, and XML output files. It is @emph{not} output implicitly in +plain text or @TeX{}; it's up to you to use @code{@@insertcopying} to +emit the copying information. See the next section for details. + +@findex copyright +The @code{@@copyright@{@}} command generates a @samp{c} inside a circle +in output formats that support this (print and HTML). In the other +formats (Info and plain text), it generates @samp{(C)}. The copyright +notice itself has the following legally defined sequence: + +@example +Copyright @copyright{} @var{years} @var{copyright-owner}. +@end example + +@cindex Copyright word, always in English +The word `Copyright' must always be written in English, even if the +document is otherwise written in another language. This is due to +international law. + +@cindex Years, in copyright line +The list of years should include all years in which a version was +completed (even if it was released in a subsequent year). Ranges are +not allowed; each year must be written out individually and in full, +separated by commas. + +@cindex Copyright holder for FSF works +@cindex Holder of copyright for FSF works +@cindex Owner of copyright for FSF works +The copyright owner (or owners) is whoever holds legal copyright on the +work. In the case of works assigned to the FSF, the owner is `Free +Software Foundation, Inc.'. + +The copyright `line' may actually be split across multiple lines, both +in the source document and in the output. This often happens for +documents with a long history, having many different years of +publication. If you do use several lines, do not indent any of them +(or anything else in the @code{@@copying} block) in the source file. + +@xref{Copyright Notices,,,maintain,GNU Maintenance Instructions}, for +additional information. + + +@node insertcopying +@subsection @code{@@insertcopying}: Include Permissions Text +@findex insertcopying +@cindex Copying text, including +@cindex Permissions text, including +@cindex Including permissions text + +The @code{@@insertcopying} command is simply written on a line by +itself, like this: + +@example +@@insertcopying +@end example + +This inserts the text previously defined by @code{@@copying}. To meet +legal requirements, it must be used on the copyright page in the printed +manual (@pxref{Copyright}). + +The @code{@@copying} command itself causes the permissions text to +appear in an Info file @emph{before} the first node. The text is also +copied into the beginning of each split Info output file, as is legally +necessary. This location implies a human reading the manual using Info +does @emph{not} see this text (except when using the advanced Info +command @kbd{g *}), but this does not matter for legal purposes, +because the text is present. + +Similarly, the @code{@@copying} text is automatically included at the +beginning of each HTML output file, as an HTML comment. Again, this +text is not visible (unless the reader views the HTML source). + +The permissions text defined by @code{@@copying} also appears +automatically at the beginning of the XML output file. + + +@node Titlepage & Copyright Page +@section Title and Copyright Pages + +In hard copy output, the manual's name and author are usually printed on +a title page. Copyright information is usually printed on the back of +the title page. + +The title and copyright pages appear in the printed manual, but not in +the Info file. Because of this, it is possible to use several slightly +obscure @TeX{} typesetting commands that cannot be used in an Info file. +In addition, this part of the beginning of a Texinfo file contains the +text of the copying permissions that appears in the printed manual. + +@cindex Title page, for plain text +@cindex Copyright page, for plain text +You may wish to include titlepage-like information for plain text +output. Simply place any such leading material between +@code{@@ifplaintext} and @code{@@end ifplaintext}; @command{makeinfo} +includes this when writing plain text (@samp{--no-headers}), along with +an @code{@@insertcopying}. + +@menu +* titlepage:: Create a title for the printed document. +* titlefont center sp:: The @code{@@titlefont}, @code{@@center}, + and @code{@@sp} commands. +* title subtitle author:: The @code{@@title}, @code{@@subtitle}, + and @code{@@author} commands. +* Copyright:: How to write the copyright notice and + include copying permissions. +* end titlepage:: Turn on page headings after the title and + copyright pages. +* headings on off:: An option for turning headings on and off + and double or single sided printing. +@end menu + + +@node titlepage +@subsection @code{@@titlepage} +@cindex Title page +@findex titlepage + +Start the material for the title page and following copyright page +with @code{@@titlepage} on a line by itself and end it with +@code{@@end titlepage} on a line by itself. + +The @code{@@end titlepage} command starts a new page and turns on page +numbering. (@xref{Headings, , Page Headings}, for details about how to +generate page headings.) All the material that you want to appear on +unnumbered pages should be put between the @code{@@titlepage} and +@code{@@end titlepage} commands. You can force the table of contents to +appear there with the @code{@@setcontentsaftertitlepage} command +(@pxref{Contents}). + +@findex page@r{, within @code{@@titlepage}} +By using the @code{@@page} command you can force a page break within the +region delineated by the @code{@@titlepage} and @code{@@end titlepage} +commands and thereby create more than one unnumbered page. This is how +the copyright page is produced. (The @code{@@titlepage} command might +perhaps have been better named the @code{@@titleandadditionalpages} +command, but that would have been rather long!) + +When you write a manual about a computer program, you should write the +version of the program to which the manual applies on the title page. +If the manual changes more frequently than the program or is independent +of it, you should also include an edition number@footnote{We have found +that it is helpful to refer to versions of independent manuals as +`editions' and versions of programs as `versions'; otherwise, we find we +are liable to confuse each other in conversation by referring to both +the documentation and the software with the same words.} for the manual. +This helps readers keep track of which manual is for which version of +the program. (The `Top' node should also contain this information; see +@ref{The Top Node}.) + +Texinfo provides two main methods for creating a title page. One method +uses the @code{@@titlefont}, @code{@@sp}, and @code{@@center} commands +to generate a title page in which the words on the page are +centered. + +The second method uses the @code{@@title}, @code{@@subtitle}, and +@code{@@author} commands to create a title page with black rules under +the title and author lines and the subtitle text set flush to the +right hand side of the page. With this method, you do not specify any +of the actual formatting of the title page. You specify the text +you want, and Texinfo does the formatting. + +You may use either method, or you may combine them; see the examples in +the sections below. + +@findex shorttitlepage +@cindex Bastard title page +@cindex Title page, bastard +For extremely simple documents, and for the bastard title page in +traditional book frontmatter, Texinfo also provides a command +@code{@@shorttitlepage} which takes the rest of the line as the title. +The argument is typeset on a page by itself and followed by a blank +page. + + +@node titlefont center sp +@subsection @code{@@titlefont}, @code{@@center}, and @code{@@sp} +@findex titlefont +@findex center +@findex sp @r{(titlepage line spacing)} + +You can use the @code{@@titlefont}, @code{@@sp}, and @code{@@center} +commands to create a title page for a printed document. (This is the +first of the two methods for creating a title page in Texinfo.) + +Use the @code{@@titlefont} command to select a large font suitable for +the title itself. You can use @code{@@titlefont} more than once if you +have an especially long title. + +For HTML output, each @code{@@titlefont} command produces an +@code{<h1>} heading, but the HTML document @code{<title>} is not +affected. For that, you must put an @code{@@settitle} command before +the @code{@@titlefont} command (@pxref{settitle}). + +@need 700 +For example: + +@example +@@titlefont@{Texinfo@} +@end example + +Use the @code{@@center} command at the beginning of a line to center +the remaining text on that line. Thus, + +@example +@@center @@titlefont@{Texinfo@} +@end example + +@noindent +centers the title, which in this example is ``Texinfo'' printed +in the title font. + +Use the @code{@@sp} command to insert vertical space. For example: + +@example +@@sp 2 +@end example + +@noindent +This inserts two blank lines on the printed page. (@xref{sp, , +@code{@@sp}}, for more information about the @code{@@sp} +command.) + +A template for this method looks like this: + +@example +@group +@@titlepage +@@sp 10 +@@center @@titlefont@{@var{name-of-manual-when-printed}@} +@@sp 2 +@@center @var{subtitle-if-any} +@@sp 2 +@@center @var{author} +@dots{} +@@end titlepage +@end group +@end example + +The spacing of the example fits an 8.5 by 11 inch manual. + +You can in fact use these commands anywhere, not just on a title page, +but since they are not logical markup commands, we don't recommend +them. + +@node title subtitle author +@subsection @code{@@title}, @code{@@subtitle}, and @code{@@author} +@findex title +@findex subtitle +@findex author + +You can use the @code{@@title}, @code{@@subtitle}, and @code{@@author} +commands to create a title page in which the vertical and horizontal +spacing is done for you automatically. This contrasts with the method +described in the previous section, in which the @code{@@sp} command is +needed to adjust vertical spacing. + +Write the @code{@@title}, @code{@@subtitle}, or @code{@@author} +commands at the beginning of a line followed by the title, subtitle, +or author. These commands are only effective in @TeX{} output; it's +an error to use them anywhere except within @code{@@titlepage}. + +The @code{@@title} command produces a line in which the title is set +flush to the left-hand side of the page in a larger than normal font. +The title is underlined with a black rule. Only a single line is +allowed; the @code{@@*} command may not be used to break the title into +two lines. To handle very long titles, you may find it profitable to +use both @code{@@title} and @code{@@titlefont}; see the final example in +this section. + +The @code{@@subtitle} command sets subtitles in a normal-sized font +flush to the right-hand side of the page. + +The @code{@@author} command sets the names of the author or authors in +a middle-sized font flush to the left-hand side of the page on a line +near the bottom of the title page. The names are underlined with a +black rule that is thinner than the rule that underlines the title. +(The black rule only occurs if the @code{@@author} command line is +followed by an @code{@@page} command line.) + +There are two ways to use the @code{@@author} command: you can write +the name or names on the remaining part of the line that starts with +an @code{@@author} command: + +@example +@@author by Jane Smith and John Doe +@end example + +@noindent +or you can write the names one above each other by using two (or more) +@code{@@author} commands: + +@example +@group +@@author Jane Smith +@@author John Doe +@end group +@end example + +@noindent +(Only the bottom name is underlined with a black rule.) + +@need 950 +A template for this method looks like this: + +@example +@group +@@titlepage +@@title @var{name-of-manual-when-printed} +@@subtitle @var{subtitle-if-any} +@@subtitle @var{second-subtitle} +@@author @var{author} +@@page +@dots{} +@@end titlepage +@end group +@end example + +You may also combine the @code{@@titlefont} method described in the +previous section and @code{@@title} method described in this one. This +may be useful if you have a very long title. Here is a real-life example: + +@example +@group +@@titlepage +@@titlefont@{GNU Software@} +@@sp 1 +@@title for MS-Windows and MS-DOS +@@subtitle Edition @@value@{e@} for Release @@value@{cde@} +@@author by Daniel Hagerty, Melissa Weisshaus +@@author and Eli Zaretskii +@end group +@end example + +@noindent +(The use of @code{@@value} here is explained in @ref{value Example}. + + +@node Copyright +@subsection Copyright Page +@cindex Copyright page +@cindex Printed permissions +@cindex Permissions, printed + +By international treaty, the copyright notice for a book must be either +on the title page or on the back of the title page. When the copyright +notice is on the back of the title page, that page is customarily not +numbered. Therefore, in Texinfo, the information on the copyright page +should be within @code{@@titlepage} and @code{@@end titlepage} +commands. + +@findex vskip @r{@TeX{} vertical skip} +@findex filll @r{@TeX{} dimension} +Use the @code{@@page} command to cause a page break. To push the +copyright notice and the other text on the copyright page towards the +bottom of the page, use the following incantation after @code{@@page}: + +@example +@@vskip 0pt plus 1filll +@end example + +@noindent +This is a @TeX{} command that is not supported by the Info formatting +commands. The @code{@@vskip} command inserts whitespace. The @samp{0pt +plus 1filll} means to put in zero points of mandatory whitespace, and as +much optional whitespace as needed to push the following text to the +bottom of the page. Note the use of three @samp{l}s in the word +@samp{filll}; this is correct. + +To insert the copyright text itself, write @code{@@insertcopying} +next (@pxref{Document Permissions}): + +@example +@@insertcopying +@end example + +Follow the copying text by the publisher, ISBN numbers, cover art +credits, and other such information. + +Here is an example putting all this together: + +@example +@@titlepage +@dots{} +@@page +@@vskip 0pt plus 1filll +@@insertcopying + +Published by @dots{} + +Cover art by @dots{} +@@end titlepage +@end example + + +@node end titlepage +@subsection Heading Generation +@findex end titlepage +@cindex Headings, page, begin to appear +@cindex Titlepage end starts headings +@cindex End titlepage starts headings + +Like all @code{@@end} commands (@pxref{Quotations and Examples}), the @code{@@end titlepage} command +must be written at the beginning of a line by itself, with only one +space between the @code{@@end} and the @code{titlepage}. It not only +marks the end of the title and copyright pages, but also causes @TeX{} +to start generating page headings and page numbers. + +To repeat what is said elsewhere, Texinfo has two standard page heading +formats, one for documents which are printed on one side of each sheet of paper +(single-sided printing), and the other for documents which are printed on both +sides of each sheet (double-sided printing). +You can specify these formats in different ways: + +@itemize @bullet +@item +The conventional way is to write an @code{@@setchapternewpage} command +before the title page commands, and then have the @code{@@end +titlepage} command start generating page headings in the manner desired. +(@xref{setchapternewpage}.) + +@item +Alternatively, you can use the @code{@@headings} command to prevent page +headings from being generated or to start them for either single or +double-sided printing. (Write an @code{@@headings} command immediately +after the @code{@@end titlepage} command. @xref{headings on off, , The +@code{@@headings} Command}, for more information.)@refill + +@item +Or, you may specify your own page heading and footing format. +@xref{Headings, , Page Headings}, for detailed +information about page headings and footings. +@end itemize + +Most documents are formatted with the standard single-sided or +double-sided format, using @code{@@setchapternewpage odd} for +double-sided printing and no @code{@@setchapternewpage} command for +single-sided printing. + + +@node headings on off +@subsection The @code{@@headings} Command +@findex headings + +The @code{@@headings} command is rarely used. It specifies what kind of +page headings and footings to print on each page. Usually, this is +controlled by the @code{@@setchapternewpage} command. You need the +@code{@@headings} command only if the @code{@@setchapternewpage} command +does not do what you want, or if you want to turn off predefined page +headings prior to defining your own. Write an @code{@@headings} command +immediately after the @code{@@end titlepage} command. + +You can use @code{@@headings} as follows: + +@table @code +@item @@headings off +Turn off printing of page headings. + +@item @@headings single +Turn on page headings appropriate for single-sided printing. + +@item @@headings double +Turn on page headings appropriate for double-sided printing. + +@item @@headings singleafter +@itemx @@headings doubleafter +Turn on @code{single} or @code{double} headings, respectively, after the +current page is output. + +@item @@headings on +Turn on page headings: @code{single} if @samp{@@setchapternewpage +on}, @code{double} otherwise. +@end table + +For example, suppose you write @code{@@setchapternewpage off} before the +@code{@@titlepage} command to tell @TeX{} to start a new chapter on the +same page as the end of the last chapter. This command also causes +@TeX{} to typeset page headers for single-sided printing. To cause +@TeX{} to typeset for double sided printing, write @code{@@headings +double} after the @code{@@end titlepage} command. + +You can stop @TeX{} from generating any page headings at all by +writing @code{@@headings off} on a line of its own immediately after the +line containing the @code{@@end titlepage} command, like this: + +@example +@@end titlepage +@@headings off +@end example + +@noindent +The @code{@@headings off} command overrides the @code{@@end titlepage} +command, which would otherwise cause @TeX{} to print page headings. + +You can also specify your own style of page heading and footing. +@xref{Headings, , Page Headings}, for more information. + + +@node Contents +@section Generating a Table of Contents +@cindex Table of contents +@cindex Contents, Table of +@cindex Short table of contents +@findex contents +@findex summarycontents +@findex shortcontents + +The @code{@@chapter}, @code{@@section}, and other structuring commands +(@pxref{Structuring}) supply the information to make up a +table of contents, but they do not cause an actual table to appear in +the manual. To do this, you must use the @code{@@contents} and/or +@code{@@summarycontents} command(s). + +@table @code +@item @@contents +Generates a table of contents in a printed manual, including all +chapters, sections, subsections, etc., as well as appendices and +unnumbered chapters. Headings generated by @code{@@majorheading}, +@code{@@chapheading}, and the other @code{@@@dots{}heading} commands +do not appear in the table of contents (@pxref{Structuring Command +Types}). + +@item @@shortcontents +@itemx @@summarycontents +(@code{@@summarycontents} is a synonym for @code{@@shortcontents}.) + +Generates a short or summary table of contents that lists only the +chapters, appendices, and unnumbered chapters. Sections, subsections +and subsubsections are omitted. Only a long manual needs a short +table of contents in addition to the full table of contents. + +@end table + +Both contents commands should be written on a line by themselves, and +are best placed near the beginning of the file, after the @code{@@end +titlepage} (@pxref{titlepage}). The contents commands automatically +generate a chapter-like heading at the top of the first table of +contents page, so don't include any sectioning command such as +@code{@@unnumbered} before them. + +Since an Info file uses menus instead of tables of contents, the Info +formatting commands ignore the contents commands. But the contents are +included in plain text output (generated by @code{makeinfo +--no-headers}), unless @code{makeinfo} is writing its output to standard +output. + +When @code{makeinfo} writes a short table of contents while producing +HTML output, the links in the short table of contents point to +corresponding entries in the full table of contents rather than the text +of the document. The links in the full table of contents point to the +main text of the document. + +In the past, the contents commands were sometimes placed at the end of +the file, after any indices and just before the @code{@@bye}, but we +no longer recommend this. + +@findex setcontentsaftertitlepage +@findex setshortcontentsaftertitlepage +@cindex Contents, after title page +@cindex Table of contents, after title page +However, since many existing Texinfo documents still do have the +@code{@@contents} at the end of the manual, if you are a user printing +a manual, you may wish to force the contents to be printed after the +title page. You can do this by specifying +@code{@@setcontentsaftertitlepage} and/or +@code{@@setshortcontentsaftertitlepage}. The first prints only the +main contents after the @code{@@end titlepage}; the second prints both +the short contents and the main contents. In either case, any +subsequent @code{@@contents} or @code{@@shortcontents} is ignored +(unless, erroneously, no @code{@@end titlepage} is ever encountered). + +You need to include the @code{@@set@dots{}contentsaftertitlepage} +commands early in the document (just after @code{@@setfilename}, for +example). We recommend using @command{texi2dvi} (@pxref{Format with +texi2dvi}) to specify this without altering the source file at all. For +example: +@example +texi2dvi --texinfo=@@setcontentsaftertitlepage foo.texi +@end example + + +@node The Top Node +@section The `Top' Node and Master Menu +@cindex Top node +@cindex Node, `Top' + +The `Top' node is the node in which a reader enters an Info manual. +As such, it should begin with a brief description of the manual +(including the version number), and end with a master menu for the +whole manual. Of course you should include any other general +information you feel a reader would find helpful. + +@findex top +It is conventional and desirable to write an @code{@@top} sectioning +command line containing the title of the document immediately after +the @code{@@node Top} line (@pxref{makeinfo top command, , The +@code{@@top} Sectioning Command}). + +The contents of the `Top' node should appear only in the online output; +none of it should appear in printed output, so enclose it between +@code{@@ifnottex} and @code{@@end ifnottex} commands. (@TeX{} does not +print either an @code{@@node} line or a menu; they appear only in Info; +strictly speaking, you are not required to enclose these parts between +@code{@@ifnottex} and @code{@@end ifnottex}, but it is simplest to do +so. @xref{Conditionals, , Conditionally Visible Text}.) + +@menu +* Top Node Example:: +* Master Menu Parts:: +@end menu + + +@node Top Node Example +@subsection Top Node Example + +@cindex Top node example + +Here is an example of a Top node. + +@example +@group +@@ifnottex +@@node Top +@@top Sample Title + +@@insertcopying +@@end ifnottex +@end group + +Additional general information. + +@group +@@menu +* First Chapter:: +* Second Chapter:: +@dots{} +* Index:: +@end group +@@end menu +@end example + + +@node Master Menu Parts +@subsection Parts of a Master Menu +@cindex Master menu +@cindex Menu, master +@cindex Parts of a master menu + +A @dfn{master menu} is a detailed main menu listing all the nodes in a +file. + +A master menu is enclosed in @code{@@menu} and @code{@@end menu} +commands and does not appear in the printed document. + +Generally, a master menu is divided into parts. + +@itemize @bullet +@item +The first part contains the major nodes in the Texinfo file: the nodes +for the chapters, chapter-like sections, and the appendices. + +@item +The second part contains nodes for the indices. + +@item +@findex detailmenu +@cindex Detailed menu +The third and subsequent parts contain a listing of the other, lower +level nodes, often ordered by chapter. This way, rather than go +through an intermediary menu, an inquirer can go directly to a +particular node when searching for specific information. These menu +items are not required; add them if you think they are a +convenience. If you do use them, put @code{@@detailmenu} before the +first one, and @code{@@end detailmenu} after the last; otherwise, +@code{makeinfo} will get confused. +@end itemize + +Each section in the menu can be introduced by a descriptive line. So +long as the line does not begin with an asterisk, it will not be +treated as a menu entry. (@xref{Writing a Menu}, for more +information.) + +For example, the master menu for this manual looks like the following +(but has many more entries): + +@example +@group +@@menu +* Copying Conditions:: Your rights. +* Overview:: Texinfo in brief. +@dots{} +@end group +@group +* Command and Variable Index:: +* General Index:: +@end group + +@group +@@detailmenu +--- The Detailed Node Listing --- + +Overview of Texinfo + +* Reporting Bugs:: @dots{} +@dots{} +@end group + +@group +Beginning a Texinfo File + +* Sample Beginning:: @dots{} +@dots{} +@@end detailmenu +@@end menu +@end group +@end example + + +@node Global Document Commands +@section Global Document Commands +@cindex Global Document Commands + +Besides the basic commands mentioned in the previous sections, here are +additional commands which affect the document as a whole. They are +generally all given before the Top node, if they are given at all. + +@menu +* documentdescription:: Document summary for the HTML output. +* setchapternewpage:: Start chapters on right-hand pages. +* paragraphindent:: Specify paragraph indentation. +* firstparagraphindent:: Suppress indentation of the first paragraph. +* exampleindent:: Specify environment indentation. +@end menu + + +@node documentdescription +@subsection @code{@@documentdescription}: Summary Text +@cindex Document description +@cindex Description of document +@cindex Summary of document +@cindex Abstract of document +@cindex <meta> HTML tag, and document description +@findex documentdescription + +When producing HTML output for a document, @command{makeinfo} writes a +@samp{<meta>} element in the @samp{<head>} to give some idea of the +content of the document. By default, this @dfn{description} is the title +of the document, taken from the @code{@@settitle} command +(@pxref{settitle}). To change this, use the @code{@@documentdescription} +environment, as in: + +@example +@@documentdescription +descriptive text. +@@end documentdescription +@end example + +@noindent +This will produce the following output in the @samp{<head>} of the HTML: + +@example +<meta name=description content="descriptive text."> +@end example + +@code{@@documentdescription} must be specified before the first node of +the document. + + +@node setchapternewpage +@subsection @code{@@setchapternewpage}: +@cindex Starting chapters +@cindex Pages, starting odd +@findex setchapternewpage + +In an officially bound book, text is usually printed on both sides of +the paper, chapters start on right-hand pages, and right-hand pages have +odd numbers. But in short reports, text often is printed only on one +side of the paper. Also in short reports, chapters sometimes do not +start on new pages, but are printed on the same page as the end of the +preceding chapter, after a small amount of vertical whitespace. + +You can use the @code{@@setchapternewpage} command with various +arguments to specify how @TeX{} should start chapters and whether it +should format headers for printing on one or both sides of the paper +(single-sided or double-sided printing). + +Write the @code{@@setchapternewpage} command at the beginning of a +line followed by its argument. + +For example, you would write the following to cause each chapter to +start on a fresh odd-numbered page: + +@example +@@setchapternewpage odd +@end example + +You can specify one of three alternatives with the +@code{@@setchapternewpage} command: + +@table @asis + +@item @code{@@setchapternewpage off} +Cause @TeX{} to typeset a new chapter on the same page as the last +chapter, after skipping some vertical whitespace. Also, cause @TeX{} to +format page headers for single-sided printing. + +@item @code{@@setchapternewpage on} +Cause @TeX{} to start new chapters on new pages and to format page +headers for single-sided printing. This is the form most often used for +short reports or personal printing. This is the default. + +@item @code{@@setchapternewpage odd} +Cause @TeX{} to start new chapters on new, odd-numbered pages +(right-handed pages) and to typeset for double-sided printing. This is +the form most often used for books and manuals. +@end table + +Texinfo does not have an @code{@@setchapternewpage even} command, +because there is no printing tradition of starting chapters or books on +an even-numbered page. + +If you don't like the default headers that @code{@@setchapternewpage} +sets, you can explicit control them with the @code{@@headings} command. +@xref{headings on off, , The @code{@@headings} Command}. + +At the beginning of a manual or book, pages are not numbered---for +example, the title and copyright pages of a book are not numbered. By +convention, table of contents and frontmatter pages are numbered with +roman numerals and not in sequence with the rest of the document. + +Since an Info file does not have pages, the @code{@@setchapternewpage} +command has no effect on it. + +We recommend not including any @code{@@setchapternewpage} command in +your manual sources at all, since the desired output is not intrinsic to +the document. For a particular hard copy run, if you don't want the +default option (no blank pages, same headers on all pages) use the +@option{--texinfo} option to @command{texi2dvi} to specify the output +you want. + + +@node paragraphindent +@subsection @code{@@paragraphindent}: Paragraph Indenting +@cindex Indenting paragraphs, control of +@cindex Paragraph indentation control +@findex paragraphindent + +The Texinfo processors may insert whitespace at the beginning of the +first line of each paragraph, thereby indenting that paragraph. You can +use the @code{@@paragraphindent} command to specify this indentation. +Write an @code{@@paragraphindent} command at the beginning of a line +followed by either @samp{asis} or a number: + +@example +@@paragraphindent @var{indent} +@end example + +The indentation is according to the value of @var{indent}: + +@table @asis +@item @code{asis} +Do not change the existing indentation (not implemented in @TeX{}). + +@item @code{none} +@itemx 0 +Omit all indentation. + +@item @var{n} +Indent by @var{n} space characters in Info output, by @var{n} ems in +@TeX{}. + +@end table + +The default value of @var{indent} is 3. @code{@@paragraphindent} is +ignored for HTML output. + +It is best to write the @code{@@paragraphindent} command before the +end-of-header line at the beginning of a Texinfo file, so the region +formatting commands indent paragraphs as specified. @xref{Start of +Header}. + +A peculiarity of the @code{texinfo-format-buffer} and +@code{texinfo-format-region} commands is that they do not indent (nor +fill) paragraphs that contain @code{@@w} or @code{@@*} commands. + + +@node firstparagraphindent +@subsection @code{@@firstparagraphindent}: Indenting After Headings +@cindex First paragraph, suppressing indentation of +@cindex Suppressing first paragraph indentation +@cindex Preventing first paragraph indentation +@cindex Indenting, suppressing of first paragraph +@cindex Headings, indentation after +@findex firstparagraphindent + +As you can see in the present manual, the first paragraph in any +section is not indented by default. Typographically, indentation is a +paragraph separator, which means that it is unnecessary when a new +section begins. This indentation is controlled with the +@code{@@firstparagraphindent} command: + +@example +@@firstparagraphindent @var{word} +@end example + +The first paragraph after a heading is indented according to the value +of @var{word}: + +@table @asis +@item @code{none} +Prevents the first paragraph from being indented (default). +This option is ignored by @command{makeinfo} if +@code{@@paragraphindent asis} is in effect. + +@item @code{insert} +Include normal paragraph indentation. This respects the paragraph +indentation set by a @code{@@paragraphindent} command +(@pxref{paragraphindent}). +@end table + +For HTML and XML output, the @code{@@firstparagraphindent} setting is +ignored. + +It is best to write the @code{@@paragraphindent} command before the +end-of-header line at the beginning of a Texinfo file, so the region +formatting commands indent paragraphs as specified. @xref{Start of +Header}. + + +@node exampleindent +@subsection @code{@@exampleindent}: Environment Indenting +@cindex Indenting environments +@cindex Environment indentation +@cindex Example indentation +@findex exampleindent + +The Texinfo processors indent each line of @code{@@example} and similar +environments. You can use the @code{@@exampleindent} command to specify +this indentation. Write an @code{@@exampleindent} command at the +beginning of a line followed by either @samp{asis} or a number: + +@example +@@exampleindent @var{indent} +@end example + +@code{@@exampleindent} is ignored for HTML output. Otherwise, the +indentation is according to the value of @var{indent}: + +@table @asis +@item @code{asis} +Do not change the existing indentation (not implemented in @TeX{}). + +@item 0 +Omit all indentation. + +@item @var{n} +Indent environments by @var{n} space characters in Info output, by +@var{n} ems in @TeX{}. + +@end table + +The default value of @var{indent} is 5 spaces in Info, and 0.4@dmn{in} +in @TeX{}, which is somewhat less. (The reduction is to help @TeX{} +fit more characters onto physical lines.) + +It is best to write the @code{@@exampleindent} command before the +end-of-header line at the beginning of a Texinfo file, so the region +formatting commands indent paragraphs as specified. @xref{Start of +Header}. + + +@node Software Copying Permissions +@section Software Copying Permissions +@cindex Software copying permissions +@cindex Copying software +@cindex Distribution +@cindex License agreement + +If the Texinfo file has a section containing the ``General Public +License'' and the distribution information and a warranty disclaimer for +the software that is documented, we recommend placing this right after +the `Top' node. The General Public License is very important to Project +GNU software. It ensures that you and others will continue to have a +right to use and share the software. + +The copying and distribution information and the disclaimer are followed +by an introduction or else by the first chapter of the manual. + +@cindex Introduction, as part of file +Although an introduction is not a required part of a Texinfo file, it +is very helpful. Ideally, it should state clearly and concisely what +the file is about and who would be interested in reading it. In +general, an introduction would follow the licensing and distribution +information, although sometimes people put it earlier in the document. + + +@node Ending a File +@chapter Ending a Texinfo File +@cindex Ending a Texinfo file +@cindex Texinfo file ending +@cindex File ending +@findex bye + +The end of a Texinfo file should include commands to create indices, +and the @code{@@bye} command to mark the last line to be processed. + +For example: + +@example +@@node Index +@@unnumbered Index + +@@printindex cp + +@@bye +@end example + +@menu +* Printing Indices & Menus:: How to print an index in hardcopy and + generate index menus in Info. +* File End:: How to mark the end of a file. +@end menu + + +@node Printing Indices & Menus +@section Printing Indices and Menus +@cindex Printing an index +@cindex Indices, printing and menus +@cindex Generating menus with indices +@cindex Menus generated with indices + +To print an index means to include it as part of a manual or Info file. +This does not happen automatically just because you use @code{@@cindex} +or other index-entry generating commands in the Texinfo file; those just +cause the raw data for the index to be accumulated. To generate an +index, you must include the @code{@@printindex} command at the place in +the document where you want the index to appear. Also, as part of the +process of creating a printed manual, you must run a program called +@code{texindex} (@pxref{Hardcopy}) to sort the raw data to produce a +sorted index file. The sorted index file is what is actually used to +print the index. + +Texinfo offers six separate types of predefined index, which suffice +in most cases. @xref{Indices}, for information on this, as well +defining your own new indices, combining indices, and, most +importantly advice on writing the actual index entries. This section +focuses on printing indices, which is done with the +@code{@@printindex} command. + +@findex printindex +@code{@@printindex} takes one argument, a two-letter index +abbreviation. It reads the corresponding sorted index file (for +printed output), and formats it appropriately into an index. + +The @code{@@printindex} command does not generate a chapter heading +for the index, since different manuals have different needs. +Consequently, you should precede the @code{@@printindex} command with +a suitable section or chapter command (usually @code{@@appendix} or +@code{@@unnumbered}) to supply the chapter heading and put the index +into the table of contents. Precede the chapter heading with an +@code{@@node} line as usual. + +For example: + +@smallexample +@group +@@node Variable Index +@@unnumbered Variable Index + +@@printindex vr +@end group + +@group +@@node Concept Index +@@unnumbered Concept Index + +@@printindex cp +@end group +@end smallexample + +If you have more than one index, we recommend placing the concept index last. + +@itemize +@item +In printed output, @code{@@printindex} produces a traditional +two-column index, with dot leaders between the index terms and page +numbers. + +@item +In Info output, @code{@@printindex} produces a special menu containing +the line number of the entry, relative to the start of the node. Info +readers can use this to go to the exact line of an entry, not just the +containing node. (Older Info readers will just go to the node.) +Here's an example: + +@smallexample +* First index entry: Top. (line 7) +@end smallexample + +@noindent The actual number of spaces is variable, to right-justify +the line number; it's been reduced here to make the line fit in the +printed manual. + +@item +In plain text output, @code{@@printindex} produces the same menu, but +the line numbers are relative to the start of the file, since that's +more convenient for that format. + +@item +In HTML and Docbook output, @code{@@printindex} produces links +to the index entries. + +@item +In XML output, it simply records the index to be printed. +@end itemize + +It's not possible to generate an index when writing to standard +output; @command{makeinfo} generates a warning in this case. + + +@node File End +@section @code{@@bye} File Ending +@findex bye + +An @code{@@bye} command terminates Texinfo processing. None of the +formatters read anything following @code{@@bye}. The @code{@@bye} +command should be on a line by itself. + +If you wish, you may follow the @code{@@bye} line with notes. These +notes will not be formatted and will not appear in either Info or a +printed manual; it is as if text after @code{@@bye} were within +@code{@@ignore} @dots{} @code{@@end ignore}. Also, you may follow the +@code{@@bye} line with a local variables list for Emacs. +@xref{Compile-Command, , Using Local Variables and the Compile Command}, +for more information. + + +@node Structuring +@chapter Chapter Structuring +@cindex Chapter structuring +@cindex Structuring of chapters + +The @dfn{chapter structuring} commands divide a document into a hierarchy of +chapters, sections, subsections, and subsubsections. These commands +generate large headings; they also provide information for the table +of contents of a printed manual (@pxref{Contents, , Generating a Table +of Contents}).@refill + +The chapter structuring commands do not create an Info node structure, +so normally you should put an @code{@@node} command immediately before +each chapter structuring command (@pxref{Nodes}). The only time you +are likely to use the chapter structuring commands without using the +node structuring commands is if you are writing a document that +contains no cross references and will never be transformed into Info +format.@refill + +It is unlikely that you will ever write a Texinfo file that is +intended only as an Info file and not as a printable document. If you +do, you might still use chapter structuring commands to create a +heading at the top of each node---but you don't need to.@refill + +@menu +* Tree Structuring:: A manual is like an upside down tree @dots{} +* Structuring Command Types:: How to divide a manual into parts. +* makeinfo top:: The @code{@@top} command, part of the `Top' node. +* chapter:: +* unnumbered & appendix:: +* majorheading & chapheading:: +* section:: +* unnumberedsec appendixsec heading:: +* subsection:: +* unnumberedsubsec appendixsubsec subheading:: +* subsubsection:: Commands for the lowest level sections. +* Raise/lower sections:: How to change commands' hierarchical level. +@end menu + + +@node Tree Structuring +@section Tree Structure of Sections +@cindex Tree structuring + +A Texinfo file is usually structured like a book with chapters, +sections, subsections, and the like. This structure can be visualized +as a tree (or rather as an upside-down tree) with the root at the top +and the levels corresponding to chapters, sections, subsection, and +subsubsections.@refill + +Here is a diagram that shows a Texinfo file with three chapters, +each of which has two sections.@refill + +@example +@group + Top + | + ------------------------------------- + | | | + Chapter 1 Chapter 2 Chapter 3 + | | | + -------- -------- -------- + | | | | | | +Section Section Section Section Section Section + 1.1 1.2 2.1 2.2 3.1 3.2 + +@end group +@end example + +In a Texinfo file that has this structure, the beginning of Chapter 2 +looks like this:@refill + +@example +@group +@@node Chapter 2, Chapter 3, Chapter 1, top +@@chapter Chapter 2 +@end group +@end example + +The chapter structuring commands are described in the sections that +follow; the @code{@@node} and @code{@@menu} commands are described in +following chapters. (@xref{Nodes}, and see @ref{Menus}.)@refill + + +@node Structuring Command Types +@section Structuring Command Types + +The chapter structuring commands fall into four groups or series, each +of which contains structuring commands corresponding to the +hierarchical levels of chapters, sections, subsections, and +subsubsections.@refill + +The four groups are the @code{@@chapter} series, the +@code{@@unnumbered} series, the @code{@@appendix} series, and the +@code{@@heading} series.@refill + +Each command produces titles that have a different appearance on the +printed page or Info file; only some of the commands produce +titles that are listed in the table of contents of a printed book or +manual.@refill + +@itemize @bullet +@item +The @code{@@chapter} and @code{@@appendix} series of commands produce +numbered or lettered entries both in the body of a printed work and in +its table of contents.@refill + +@item +The @code{@@unnumbered} series of commands produce unnumbered entries +both in the body of a printed work and in its table of contents. The +@code{@@top} command, which has a special use, is a member of this +series (@pxref{makeinfo top, , @code{@@top}}). An @code{@@unnumbered} +section should be associated with a node and be a normal part of the +document structure. + +@item +The @code{@@heading} series of commands produce simple unnumbered +headings that do not appear in a table of contents, are not associated +with nodes, and cannot be cross-referenced. The heading commands +never start a new page. + +@item +The @code{@@majorheading} command is similar to @code{@@chapheading}, +except that it generates a larger vertical whitespace before the +heading. + +@item +When an @code{@@setchapternewpage} command says to do so, the +@code{@@chapter}, @code{@@unnumbered}, and @code{@@appendix} commands +start new pages in the printed manual; the @code{@@heading} commands +do not.@refill +@end itemize + +Here are the four groups of chapter structuring commands: + +@tex +{\globaldefs = 1 \smallfonts} +@end tex + +@multitable @columnfractions .19 .30 .29 .22 +@item @tab @tab @tab No new page +@item @i{Numbered} @tab @i{Unnumbered} @tab @i{Lettered/numbered} @tab @i{Unnumbered} +@item In contents @tab In contents @tab In contents @tab Not in contents +@item @tab @code{@@top} @tab @tab @code{@@majorheading} +@item @code{@@chapter} @tab @code{@@unnumbered} @tab @code{@@appendix} @tab @code{@@chapheading} +@item @code{@@section} @tab @code{@@unnumberedsec} @tab @code{@@appendixsec} @tab @code{@@heading} +@item @code{@@subsection} @tab @code{@@unnumberedsubsec} @tab @code{@@appendixsubsec} @tab @code{@@subheading} +@item @code{@@subsubsection} @tab @code{@@unnumberedsubsubsec} @tab @code{@@appendixsubsubsec} @tab @code{@@subsubheading} +@end multitable +@tex +{\globaldefs = 1 \textfonts} +@end tex + + +@node makeinfo top +@section @code{@@top} + +The @code{@@top} command is a special sectioning command that you use +only after an @samp{@@node Top} line at the beginning of a Texinfo file. +The @code{@@top} command tells the @code{makeinfo} formatter which node +is the `Top' node, so it can use it as the root of the node tree if your +manual uses implicit node pointers. It has the same typesetting effect as +@code{@@unnumbered} (@pxref{unnumbered & appendix, , @code{@@unnumbered} +and @code{@@appendix}}). For detailed information, see @ref{makeinfo +top command, , The @code{@@top} Command}. + +The @code{@@top} node and its menu (if any) is conventionally wrapped in +an @code{@@ifnottex} conditional so that it will appear only in Info and +HTML output, not @TeX{}. + + +@node chapter +@comment node-name, next, previous, up +@section @code{@@chapter} +@findex chapter + +@code{@@chapter} identifies a chapter in the document. Write the +command at the beginning of a line and follow it on the same line by +the title of the chapter.@refill + +For example, this chapter in this manual is entitled ``Chapter +Structuring''; the @code{@@chapter} line looks like this:@refill + +@example +@@chapter Chapter Structuring +@end example + +In @TeX{}, the @code{@@chapter} command creates a chapter in the +document, specifying the chapter title. The chapter is numbered +automatically.@refill + +In Info, the @code{@@chapter} command causes the title to appear on a +line by itself, with a line of asterisks inserted underneath. Thus, +in Info, the above example produces the following output:@refill + +@example +Chapter Structuring +******************* +@end example + +@findex centerchap +Texinfo also provides a command @code{@@centerchap}, which is analogous +to @code{@@unnumbered}, but centers its argument in the printed output. +This kind of stylistic choice is not usually offered by Texinfo. +@c but the Hacker's Dictionary wanted it ... + + +@node unnumbered & appendix +@section @code{@@unnumbered} and @code{@@appendix} +@findex unnumbered +@findex appendix + +Use the @code{@@unnumbered} command to create a chapter that appears +in a printed manual without chapter numbers of any kind. Use the +@code{@@appendix} command to create an appendix in a printed manual +that is labelled by letter (`A', `B', @dots{}) instead of by number. + +Write an @code{@@appendix} or @code{@@unnumbered} command at the +beginning of a line and follow it on the same line by the title, as +you would if you were creating a chapter. + + +@node majorheading & chapheading +@section @code{@@majorheading}, @code{@@chapheading} +@findex majorheading +@findex chapheading + +The @code{@@majorheading} and @code{@@chapheading} commands put +chapter-like headings in the body of a document.@refill + +However, neither command causes @TeX{} to produce a numbered heading +or an entry in the table of contents; and neither command causes +@TeX{} to start a new page in a printed manual.@refill + +In @TeX{}, an @code{@@majorheading} command generates a larger vertical +whitespace before the heading than an @code{@@chapheading} command but +is otherwise the same. + +In Info, +the @code{@@majorheading} and +@code{@@chapheading} commands are equivalent to +@code{@@chapter}: the title is printed on a line by itself with a line +of asterisks underneath. (@xref{chapter, , @code{@@chapter}}.)@refill + + +@node section +@section @code{@@section} +@findex section + +A @code{@@section} command identifies a section within a chapter unit, +whether created with @code{@@chapter}, @code{@@unnumbered}, or +@code{@@appendix}, following the numbering scheme of the chapter-level +command. Thus, within a @code{@@chapter} chapter numbered `1', the +section is numbered like `1.2'; within an @code{@@appendix} +``chapter'' labeled `A', the section is numbered like `A.2'; within an +@code{@@unnumbered} chapter, the section gets no number. + +For example, this section is headed with an @code{@@section} command +and looks like this in the Texinfo file: + +@example +@@section @@code@{@@@@section@} +@end example + +To create a section, write the @code{@@section} command at the +beginning of a line and follow it on the same line by the section +title. The output is underlined with @samp{=} in Info. + +Thus, + +@example +@@section This is a section +@end example + +@noindent +might produce the following in Info: + +@example +@group +5.7 This is a section +===================== +@end group +@end example + + +@node unnumberedsec appendixsec heading +@section @code{@@unnumberedsec}, @code{@@appendixsec}, @code{@@heading} +@findex unnumberedsec +@findex appendixsec +@findex heading + +The @code{@@unnumberedsec}, @code{@@appendixsec}, and @code{@@heading} +commands are, respectively, the unnumbered, appendix-like, and +heading-like equivalents of the @code{@@section} command, as described +in the previous section. + +@table @code +@item @@unnumberedsec +The @code{@@unnumberedsec} command may be used within an +unnumbered chapter or within a regular chapter or appendix to +provide an unnumbered section.@refill + +@item @@appendixsec +@itemx @@appendixsection +@code{@@appendixsection} is a longer spelling of the +@code{@@appendixsec} command; the two are synonymous.@refill +@findex appendixsection + +Conventionally, the @code{@@appendixsec} or @code{@@appendixsection} +command is used only within appendices.@refill + +@item @@heading +You may use the @code{@@heading} command anywhere you wish for a +section-style heading that will not appear in the table of contents.@refill +@end table + +@code{@@unnumberedsec} and @code{@@appendixsec} do not need to be used +in ordinary circumstances, because @code{@@section} may also be used +within @code{@@unnumbered} and @code{@@appendix} chapters; again, see +the previous section. + + +@node subsection +@section The @code{@@subsection} Command +@findex subsection + +Subsections are to sections as sections are to chapters. +(@xref{section, , @code{@@section}}.) In Info, subsection titles are +underlined with @samp{-}. For example, + +@example +@@subsection This is a subsection +@end example + +@noindent +produces + +@example +@group +1.2.3 This is a subsection +-------------------------- +@end group +@end example + +In a printed manual, subsections are listed in the table of contents +and are numbered three levels deep.@refill + + +@node unnumberedsubsec appendixsubsec subheading +@section The @code{@@subsection}-like Commands +@cindex Subsection-like commands +@findex unnumberedsubsec +@findex appendixsubsec +@findex subheading + +The @code{@@unnumberedsubsec}, @code{@@appendixsubsec}, and +@code{@@subheading} commands are, respectively, the unnumbered, +appendix-like, and heading-like equivalents of the @code{@@subsection} +command. (@xref{subsection, , @code{@@subsection}}.) + +In Info, the @code{@@subsection}-like commands generate a title +underlined with hyphens. In a printed manual, an @code{@@subheading} +command produces a heading like that of a subsection except that it is +not numbered and does not appear in the table of contents. Similarly, +an @code{@@unnumberedsubsec} command produces an unnumbered heading like +that of a subsection and an @code{@@appendixsubsec} command produces a +subsection-like heading labelled with a letter and numbers; both of +these commands produce headings that appear in the table of +contents. + +@code{@@unnumberedsubsec} and @code{@@appendixsubsec} do not need to +be used in ordinary circumstances, because @code{@@subsection} may +also be used within sections of @code{@@unnumbered} and +@code{@@appendix} chapters (@pxref{section,,@code{section}}). + + +@node subsubsection +@section The `subsub' Commands +@cindex Subsub commands +@findex subsubsection +@findex unnumberedsubsubsec +@findex appendixsubsubsec +@findex subsubheading + +The fourth and lowest level sectioning commands in Texinfo are the +`subsub' commands. They are:@refill + +@table @code +@item @@subsubsection +Subsubsections are to subsections as subsections are to sections. +(@xref{subsection, , @code{@@subsection}}.) In a printed manual, +subsubsection titles appear in the table of contents and are numbered +four levels deep.@refill + +@item @@unnumberedsubsubsec +Unnumbered subsubsection titles appear in the table of contents of a +printed manual, but lack numbers. Otherwise, unnumbered +subsubsections are the same as subsubsections. In Info, unnumbered +subsubsections look exactly like ordinary subsubsections.@refill + +@item @@appendixsubsubsec +Conventionally, appendix commands are used only for appendices and are +lettered and numbered appropriately in a printed manual. They also +appear in the table of contents. In Info, appendix subsubsections look +exactly like ordinary subsubsections.@refill + +@item @@subsubheading +The @code{@@subsubheading} command may be used anywhere that you need +a small heading that will not appear in the table of contents. In +Info, subsubheadings look exactly like ordinary subsubsection +headings.@refill +@end table + +@code{@@unnumberedsubsubsec} and @code{@@appendixsubsubsec} do not +need to be used in ordinary circumstances, because +@code{@@subsubsection} may also be used within subsections of +@code{@@unnumbered} and @code{@@appendix} chapters +(@pxref{section,,@code{section}}). + + +In Info, `subsub' titles are underlined with periods. +For example,@refill + +@example +@@subsubsection This is a subsubsection +@end example + +@noindent +produces + +@example +@group +1.2.3.4 This is a subsubsection +............................... +@end group +@end example + + +@node Raise/lower sections +@section @code{@@raisesections} and @code{@@lowersections} +@findex raisesections +@findex lowersections +@cindex Raising and lowering sections +@cindex Lowering and raising sections +@cindex Sections, raising and lowering + +The @code{@@raisesections} and @code{@@lowersections} commands +implicitly raise and lower the hierarchical level of following +chapters, sections and the other sectioning commands. + +That is, the @code{@@raisesections} command changes sections to +chapters, subsections to sections, and so on. Conversely, the +@code{@@lowersections} command changes chapters to sections, sections +to subsections, and so on. Thus, an @code{@@lowersections} command +cancels an @code{@@raisesections} command, and vice versa. + +@cindex Include files, and section levels +You can use @code{@@lowersections} to include text written as an outer +or standalone Texinfo file in another Texinfo file as an inner, +included file. Typical usage looks like this: + +@example +@@lowersections +@@include somefile.texi +@@raisesections +@end example + +@noindent (Without the @code{@@raisesections}, all the subsequent +sections in the document would be lowered.) + +If the included file being lowered has a @code{@@top} node, you'll +need to conditionalize its inclusion with a flag (@pxref{set value}). + +Another difficulty can arise with documents that use the (recommended) +feature of @command{makeinfo} for implicitly determining node +pointers. Since @command{makeinfo} must assume a hierarchically +organized document to determine the pointers, you cannot just +arbitrarily sprinkle @code{@@raisesections} and @code{@@lowersections} +commands in the document. The final result has to have menus that +take the raising and lowering into account. Therefore, as a practical +matter, you generally only want to raise or lower large chunks, +usually in external files as shown above. + +Repeated use of the commands continue to raise or lower the +hierarchical level a step at a time. An attempt to raise above +`chapter' reproduces chapter commands; an attempt to lower below +`subsubsection' reproduces subsubsection commands. Also, lowered +subsubsections and raised chapters will not work with +@command{makeinfo}'s feature of implicitly determining node pointers, +since the menu structure won't be correct. + +Write each @code{@@raisesections} and @code{@@lowersections} command +on a line of its own. + + +@node Nodes +@chapter Nodes + +@dfn{Nodes} are the primary segments of a Texinfo file. They do not +in and of themselves impose a hierarchical or any other kind of +structure on a file. Nodes contain @dfn{node pointers} that name +other nodes, and can contain @dfn{menus} which are lists of nodes. In +Info, the movement commands can carry you to a pointed-to node or to a +node listed in a menu. + +Node pointers and menus provide structure for Info files just as +chapters, sections, subsections, and the like, provide structure for +printed books. + +Because node names are used in cross-references, it is not desirable +to casually change them. Such name changes invalidate references from +other manuals, from mail archives, and so on. + +@menu +* Two Paths:: Different commands to structure + Info output and printed output. +* Node Menu Illustration:: A diagram, and sample nodes and menus. +* node:: Creating nodes, in detail. +* makeinfo Pointer Creation:: Letting makeinfo determine node pointers. +* anchor:: Defining arbitrary cross-reference targets. +@end menu + + +@node Two Paths +@section Two Paths + +The node and menu commands and the chapter structuring commands are +technically independent of each other: + +@itemize @bullet +@item +In Info, node and menu commands provide structure. The chapter +structuring commands generate headings with different kinds of +underlining---asterisks for chapters, hyphens for sections, and so on; +they do nothing else.@refill + +@item +In @TeX{}, the chapter structuring commands generate chapter and section +numbers and tables of contents. The node and menu commands provide +information for cross references; they do nothing else.@refill +@end itemize + +You can use node pointers and menus to structure an Info file any way +you want; and you can write a Texinfo file so that its Info output has a +different structure than its printed output. However, virtually all +Texinfo files are written such that the structure for the Info output +corresponds to the structure for the printed output. It is neither +convenient nor understandable to the reader to do otherwise.@refill + +Generally, printed output is structured in a tree-like hierarchy in +which the chapters are the major limbs from which the sections branch +out. Similarly, node pointers and menus are organized to create a +matching structure in the Info output.@refill + + +@node Node Menu Illustration +@section Node and Menu Illustration + +Here is a copy of the diagram shown earlier that illustrates a Texinfo +file with three chapters, each of which contains two sections.@refill + +The ``root'' is at the top of the diagram and the ``leaves'' are at the +bottom. This is how such a diagram is drawn conventionally; it +illustrates an upside-down tree. For this reason, the root node is +called the `Top' node, and `Up' node pointers carry you closer to the +root.@refill + +@example +@group + Top + | + ------------------------------------- + | | | + Chapter 1 Chapter 2 Chapter 3 + | | | + -------- -------- -------- + | | | | | | +Section Section Section Section Section Section + 1.1 1.2 2.1 2.2 3.1 3.2 +@end group +@end example + +The fully-written command to start Chapter 2 would be this: + +@example +@group +@@node Chapter 2, Chapter 3, Chapter 1, Top +@@comment node-name, next, previous, up +@end group +@end example + +@noindent +This @code{@@node} line says that the name of this node is ``Chapter +2'', the name of the `Next' node is ``Chapter 3'', the name of the +`Previous' node is ``Chapter 1'', and the name of the `Up' node is +``Top''. You can omit writing out these node names if your document is +hierarchically organized (@pxref{makeinfo Pointer Creation}), but the +pointer relationships still obtain. + +@quotation Note +@strong{Please Note:} `Next' refers to the next node at the same +hierarchical level in the manual, not necessarily to the next node +within the Texinfo file. In the Texinfo file, the subsequent node may +be at a lower level---a section-level node most often follows a +chapter-level node, for example. `Next' and `Previous' refer to nodes +at the @emph{same} hierarchical level. (The `Top' node contains the +exception to this rule. Since the `Top' node is the only node at that +level, `Next' refers to the first following node, which is almost always +a chapter or chapter-level node.)@refill +@end quotation + +To go to Sections 2.1 and 2.2 using Info, you need a menu inside Chapter +2. (@xref{Menus}.) You would write the menu just +before the beginning of Section 2.1, like this:@refill + +@example +@group + @@menu + * Sect. 2.1:: Description of this section. + * Sect. 2.2:: + @@end menu +@end group +@end example + +Write the node for Sect. 2.1 like this:@refill + +@example +@group + @@node Sect. 2.1, Sect. 2.2, Chapter 2, Chapter 2 + @@comment node-name, next, previous, up +@end group +@end example + +In Info format, the `Next' and `Previous' pointers of a node usually +lead to other nodes at the same level---from chapter to chapter or from +section to section (sometimes, as shown, the `Previous' pointer points +up); an `Up' pointer usually leads to a node at the level above (closer +to the `Top' node); and a `Menu' leads to nodes at a level below (closer +to `leaves'). (A cross reference can point to a node at any level; +see @ref{Cross References}.)@refill + +Usually, an @code{@@node} command and a chapter structuring command are +used in sequence, along with indexing commands. (You may follow the +@code{@@node} line with a comment line that reminds you which pointer is +which.)@refill + +Here is the beginning of the chapter in this manual called ``Ending a +Texinfo File''. This shows an @code{@@node} line followed by a comment +line, an @code{@@chapter} line, and then by indexing lines.@refill + +@example +@group +@@node Ending a File, Structuring, Beginning a File, Top +@@comment node-name, next, previous, up +@@chapter Ending a Texinfo File +@@cindex Ending a Texinfo file +@@cindex Texinfo file ending +@@cindex File ending +@end group +@end example + + +@node node +@section The @code{@@node} Command + +@cindex Node, defined +@findex node + +A @dfn{node} is a segment of text that begins at an @code{@@node} +command and continues until the next @code{@@node} command. The +definition of node is different from that for chapter or section. A +chapter may contain sections and a section may contain subsections; +but a node cannot contain subnodes; the text of a node continues only +until the next @code{@@node} command in the file. A node usually +contains only one chapter structuring command, the one that follows +the @code{@@node} line. On the other hand, in printed output nodes +are used only for cross references, so a chapter or section may +contain any number of nodes. Indeed, a chapter usually contains +several nodes, one for each section, subsection, and +subsubsection. + +To specify a node, write an @code{@@node} command at the beginning of +a line, and follow it with up to four arguments, separated by commas, +on the rest of the same line. The first argument is required; it is +the name of this node (for details of node names, @pxref{Node Line +Requirements}). The subsequent arguments are the names of the `Next', +`Previous', and `Up' pointers, in that order, and may be omitted if +your Texinfo document is hierarchically organized (@pxref{makeinfo +Pointer Creation}). + +@opindex accesskey@r{, in HTML output} +Whether the node pointers are specified implicitly or explicitly, the +HTML output from @command{makeinfo} for each node includes links to +the `Next', `Previous', and `Up' nodes. The HTML also uses the +@code{accesskey} attribute with the values @samp{n}, @samp{p}, and +@samp{u} respectively. This allows people using web browsers to +follow the nagivation using (typically) @kbd{M-@var{letter}}, e.g., +@kbd{M-n} for the `Next' node, from anywhere within the node. + +You may insert spaces before each name on the @code{@@node} line if +you wish; the spaces are ignored. You must write the name of the node +and (if present) the names of the `Next', `Previous', and `Up' +pointers all on the same line. Otherwise, the formatters fail. +(@inforef{Top, info, info}, for more information about nodes in Info.) + +Usually, you write one of the chapter-structuring command lines +immediately after an @code{@@node} line---for example, an +@code{@@section} or @code{@@subsection} line. (@xref{Structuring +Command Types}.) + +@TeX{} uses @code{@@node} lines to identify the names to use for cross +references. For this reason, you must write @code{@@node} lines in a +Texinfo file that you intend to format for printing, even if you do not +intend to format it for Info. (Cross references, such as the one at the +end of this sentence, are made with @code{@@xref} and related commands; +see @ref{Cross References}.) + +@menu +* Node Names:: How to choose node and pointer names. +* Writing a Node:: How to write an @code{@@node} line. +* Node Line Tips:: Keep names short. +* Node Line Requirements:: Keep names unique, without @@-commands. +* First Node:: How to write a `Top' node. +* makeinfo top command:: How to use the @code{@@top} command. +@end menu + + +@node Node Names +@subsection Choosing Node and Pointer Names + +@cindex Node names, choosing +The name of a node identifies the node (for details of node names, +@pxref{Node Line Requirements}). The pointers enable you to reach +other nodes and consist simply of the names of those nodes. + +Normally, a node's `Up' pointer contains the name of the node whose +menu mentions that node. The node's `Next' pointer contains the name +of the node that follows the present node in that menu and its +`Previous' pointer contains the name of the node that precedes it in +that menu. When a node's `Previous' node is the same as its `Up' +node, both node pointers name the same node. + +Usually, the first node of a Texinfo file is the `Top' node, and its +`Up' and `Previous' pointers point to the @file{dir} file, which +contains the main menu for all of Info. + +The `Top' node itself contains the main or master menu for the manual. +Also, it is helpful to include a brief description of the manual in the +`Top' node. @xref{First Node}, for information on how to write the +first node of a Texinfo file. + +Even when you explicitly specify all pointers, that does not mean you +can write the nodes in the Texinfo source file in an arbitrary order! +Because @TeX{} processes the file sequentially, irrespective of node +pointers, you must write the nodes in the order you wish them to appear +in the output. + + +@node Writing a Node +@subsection How to Write an @code{@@node} Line +@cindex Writing an @code{@@node} line +@cindex @code{@@node} line writing +@cindex Node line writing + +The easiest way to write an @code{@@node} line is to write @code{@@node} +at the beginning of a line and then the name of the node, like +this: + +@example +@@node @var{node-name} +@end example + +If you are using GNU Emacs, you can use the update node commands +provided by Texinfo mode to insert the names of the pointers; or you +can leave the pointers out of the Texinfo file and let @code{makeinfo} +insert node pointers into the Info file it creates. (@xref{Texinfo +Mode}, and @ref{makeinfo Pointer Creation}.) + +Alternatively, you can insert the `Next', `Previous', and `Up' +pointers yourself. If you do this, you may find it helpful to use the +Texinfo mode keyboard command @kbd{C-c C-c n}. This command inserts +@samp{@@node} and a comment line listing the names of the pointers in +their proper order. The comment line helps you keep track of which +arguments are for which pointers. This comment line is especially useful +if you are not familiar with Texinfo. + +The template for a fully-written-out node line with `Next', `Previous', +and `Up' pointers looks like this: + +@example +@@node @var{node-name}, @var{next}, @var{previous}, @var{up} +@end example + +The @var{node-name} argument must be present, but the others are +optional. If you wish to specify some but not others, just insert +commas as needed, as in: @samp{@@node mynode,,,uppernode}. However, +we recommend leaving off all the pointers and letting @code{makeinfo} +determine them, as described above. + +If you wish, you can ignore @code{@@node} lines altogether in your first +draft and then use the @code{texinfo-insert-node-lines} command to +create @code{@@node} lines for you. However, we do not recommend this +practice. It is better to name the node itself at the same time that +you write a segment so you can easily make cross references. A large +number of cross references are an especially important feature of a good +Info file. + +After you have inserted an @code{@@node} line, you should immediately +write an @@-command for the chapter or section and insert its name. +Next (and this is important!), put in several index entries. Usually, +you will find at least two and often as many as four or five ways of +referring to the node in the index. Use them all. This will make it +much easier for people to find the node. + + +@node Node Line Tips +@subsection @code{@@node} Line Tips + +Here are three suggestions: + +@itemize @bullet +@item +Try to pick node names that are informative but short.@refill + +In the Info file, the file name, node name, and pointer names are all +inserted on one line, which may run into the right edge of the window. +(This does not cause a problem with Info, but is ugly.)@refill + +@item +Try to pick node names that differ from each other near the beginnings +of their names. This way, it is easy to use automatic name completion in +Info.@refill + +@item +By convention, node names are capitalized just as they would be for +section or chapter titles---initial and significant words are +capitalized; others are not.@refill +@end itemize + + +@node Node Line Requirements +@subsection @code{@@node} Line Requirements + +@cindex Node line requirements +@cindex Restrictions on node names +Here are several requirements for @code{@@node} lines: + +@itemize @bullet +@cindex Unique nodename requirement +@cindex Node name must be unique +@item +All the node names for a single Info file must be unique. + +Duplicates confuse the Info movement commands. This means, for +example, that if you end every chapter with a summary, you must name +each summary node differently. You cannot just call each one +``Summary''. You may, however, duplicate the titles of chapters, sections, +and the like. Thus you can end each chapter in a book with a section +called ``Summary'', so long as the node names for those sections are all +different. + +@item +A pointer name must be the name of a node. + +The node to which a pointer points may come before or after the +node containing the pointer. + +@cindex @@-commands in nodename +@cindex Node name, should not contain @@-commands +@item +@@-commands in node names are not allowed. This includes punctuation +characters that are escaped with a @samp{@@}, such as @code{@@} and +@code{@{}, and accent commands such as @samp{@@'}. (For a few cases +when this is useful, Texinfo has limited support for using +@w{@@-commands} in node names; see @ref{Pointer Validation}.) Perhaps +this limitation will be removed some day. + +@item +@cindex Colon in nodename +@cindex Comma in nodename +@cindex Parentheses in nodename +@cindex Period in nodename +@cindex Characters, invalid in node name +@cindex Invalid characters in node names +@cindex Node names, invalid characters in +Unfortunately, you cannot use periods, commas, colons or parentheses +within a node name; these confuse the Texinfo processors. Perhaps +this limitation will be removed some day, too. + +@need 700 +For example, the following is a section title in this manual: + +@smallexample +@@code@{@@@@unnumberedsec@}, @@code@{@@@@appendixsec@}, @@code@{@@@@heading@} +@end smallexample + +@noindent +But the corresponding node name lacks the commas and the @@'s: + +@smallexample +unnumberedsec appendixsec heading +@end smallexample + +@cindex Case in node name +@item +Case is significant in node names. + +@cindex White space in node name +@cindex Spaces in node name +Spaces before and after names on the @samp{@@node} line are ignored, +but spaces ``inside'' a name are significant. For example: + +@example +@@node foo bar, +@@node foo bar , +@@node foo bar , +@end example + +@noindent all define the same node, @samp{foo bar}. References to the +node should all use that name, without the leading or trailing spaces, +but with the internal spaces. +@end itemize + + +@node First Node +@subsection The First Node +@cindex Top node is first +@cindex First node + +The first node of a Texinfo file is the @dfn{Top} node, except in an +included file (@pxref{Include Files}). The Top node should contain a +short summary, copying permissions, and a master menu. @xref{The Top +Node}, for more information on the Top node contents and examples. + +Here is a description of the node pointers to be used in the Top node: + +@itemize @bullet + +@item +@cindex Up node of Top node +@cindex (dir) as Up node of Top node +The Top node (which must be named @samp{top} or @samp{Top}) should have +as its `Up' node the name of a node in another file, where there is a +menu that leads to this file. Specify the file name in parentheses. + +Usually, all Info files are installed in the same Info directory tree; +in this case, use @samp{(dir)} as the parent of the Top node; this is +short for @samp{(dir)top}, and specifies the Top node in the @file{dir} +file, which contains the main menu for the Info system as a whole. + +@item +@cindex Prev node of Top node +The `Prev' node of the Top node should also be your @samp{(dir)} file. + +@item +@cindex Next node of Top node +The `Next' node of the Top node should be the first chapter in your +document. + +@end itemize + +@xref{Installing an Info File}, for more information about installing +an Info file in the @file{info} directory. + +It is usually best to leave the pointers off entirely and let the +tools implicitly define them, with this simple result: + +@example +@@node Top +@end example + + +@node makeinfo top command +@subsection The @code{@@top} Sectioning Command +@findex top @r{(@@-command)} + +A special sectioning command, @code{@@top} should be used with the +@code{@@node Top} line. The @code{@@top} sectioning command tells +@code{makeinfo} that it marks the `Top' node in the file. It provides +the information that @code{makeinfo} needs to insert node pointers +automatically. Write the @code{@@top} command at the beginning of the +line immediately following the @code{@@node Top} line. Write the title +on the remaining part of the same line as the @code{@@top} command. + +In Info, the @code{@@top} sectioning command causes the title to appear +on a line by itself, with a line of asterisks inserted underneath, as +other sectioning commands do. + +In @TeX{} and @code{texinfo-format-buffer}, the @code{@@top} +sectioning command is merely a synonym for @code{@@unnumbered}. +Neither of these formatters require an @code{@@top} command, and do +nothing special with it. You can use @code{@@chapter} or +@code{@@unnumbered} after the @code{@@node Top} line when you use +these formatters. Also, you can use @code{@@chapter} or +@code{@@unnumbered} when you use the Texinfo updating commands to +create or update pointers and menus. + +Thus, in practice, a Top node starts like this: + +@example +@@node Top +@@top Your Manual Title +@end example + + +@node makeinfo Pointer Creation +@section Creating Pointers with @code{makeinfo} +@cindex Creating pointers with @code{makeinfo} +@cindex Pointer creation with @code{makeinfo} +@cindex Automatic pointer creation with @code{makeinfo} + +The @code{makeinfo} program has a feature for automatically +determining node pointers for a hierarchically organized document. We +highly recommend using it. + +When you take advantage of this feature, you do not need to write the +`Next', `Previous', and `Up' pointers after the name of a node. +However, you must write a sectioning command, such as @code{@@chapter} +or @code{@@section}, on the line immediately following each truncated +@code{@@node} line (except that comment lines may intervene). + +In addition, you must follow the `Top' @code{@@node} line with a line +beginning with @code{@@top} to mark the `Top' node in the +file. @xref{makeinfo top, , @code{@@top}}. + +Finally, you must write the name of each node (except for the `Top' +node) in a menu that is one or more hierarchical levels above the +node's hierarchical level. + +@cindex Detail menu +@findex detailmenu +If you use a detailed menu in your master menu (@pxref{Master Menu +Parts}), mark it with the @code{@@detailmenu @@dots@{@} @@end +detailmenu} environment, or @command{makeinfo} will get confused, +typically about the last and/or first node in the document. + +This implicit node pointer creation feature in @code{makeinfo} +relieves you from the need to update menus and pointers manually or +with Texinfo mode commands. (@xref{Updating Nodes and Menus}.) + +In most cases, you will want to take advantage of this feature and not +redundantly specify node pointers. However, Texinfo documents are not +required to be organized hierarchically or in fact to contain +sectioning commands at all (for example, if you never intend the +document to be printed). The special procedure for handling the short +text before a menu (@pxref{Menus}) also disables this +feature, for that group of nodes. In those cases, you will need to +explicitly specify all pointers. + +@node anchor +@section @code{@@anchor}: Defining Arbitrary Cross-reference Targets + +@findex anchor +@cindex Anchors +@cindex Cross-reference targets, arbitrary +@cindex Targets for cross-references, arbitrary + +An @dfn{anchor} is a position in your document, labeled so that +cross-references can refer to it, just as they can to nodes. You create +an anchor with the @code{@@anchor} command, and give the label as a +normal brace-delimited argument. For example: + +@example +This marks the @@anchor@{x-spot@}spot. +@dots{} +@@xref@{x-spot,,the spot@}. +@end example + +@noindent produces: + +@example +This marks the spot. +@dots{} +See [the spot], page 1. +@end example + +As you can see, the @code{@@anchor} command itself produces no output. +This example defines an anchor `x-spot' just before the word `spot'. +You can refer to it later with an @code{@@xref} or other cross-reference +command, as shown. @xref{Cross References}, for details on the +cross-reference commands. + +It is best to put @code{@@anchor} commands just before the position you +wish to refer to; that way, the reader's eye is led on to the correct +text when they jump to the anchor. You can put the @code{@@anchor} +command on a line by itself if that helps readability of the source. +Whitespace (including newlines) is ignored after @code{@@anchor}. + +Anchor names and node names may not conflict. Anchors and nodes are +given similar treatment in some ways; for example, the @code{goto-node} +command in standalone Info takes either an anchor name or a node name as +an argument. (@xref{goto-node,,,info-stnd,GNU Info}.) + +Also like node names, anchor names cannot include some characters +(@pxref{Node Line Requirements}). + + +@node Menus +@chapter Menus +@cindex Menus +@findex menu + +@dfn{Menus} contain pointers to subordinate nodes. In online output, +you use menus to go to such nodes. Menus have no effect in printed +manuals and do not appear in them. + +A node with a menu should not contain much text. If you find yourself +writing a lot of text before a menu, we generally recommend moving +most of the text into a new subnode---all but a paragraph or two. +Otherwise, a reader with a terminal that displays only a few lines may +miss the menu and its associated text. As a practical matter, it is +best to locate a menu within 20 or so lines of the beginning of the +node. + +@menu +* Menu Location:: Menus go at the ends of short nodes. +* Writing a Menu:: What is a menu? +* Menu Parts:: A menu entry has three parts. +* Less Cluttered Menu Entry:: Two part menu entry. +* Menu Example:: Two and three part menu entries. +* Other Info Files:: How to refer to a different Info file. +@end menu + + +@node Menu Location +@section Menu Location +@cindex Menu location +@cindex Location of menus + +A menu must be located at the end of a node, without any regular text +or additional commands between the @code{@@end menu} and the beginning +of the next node. (As a consequence, there may be at most one menu in +a node.) + +@cindex Info format, and menus +This is actually a useful restriction, since a reader who uses the +menu could easily miss any such text. Technically, it is necessary +because in Info format, there is no marker for the end of a menu, so +Info-reading programs would have no way to know when the menu ends and +normal text resumes. + +@cindex Hierarchical documents, and menus +Technically, menus can carry you to any node, regardless of the +structure of the document; even to nodes in a different Info file. +However, we do not recommend ever making use of this, because the +@command{makeinfo} implicit pointer creation feature (@pxref{makeinfo +Pointer Creation}) and GNU Emacs Texinfo mode updating commands work +only to create menus of subordinate nodes in a hierarchically +structured document. Instead, use cross references to refer to +arbitrary nodes. + +In the past, we recommended using a @samp{@@heading} command within an +@code{@@ifinfo} conditional instead of the normal sectioning commands +after a very short node with a menu. This had the advantage of making +the printed output look better, because there was no very short text +between two headings on the page. But this also does not work with +@command{makeinfo}'s implicit pointer creation, and it also makes the +XML output incorrect, since it does not reflect the true document +structure. So, regrettably, we can no longer recommend this. + + +@node Writing a Menu +@section Writing a Menu +@cindex Writing a menu +@cindex Menu writing + +A menu consists of an @code{@@menu} command on a line by itself +followed by menu entry lines or menu comment lines and then by an +@code{@@end menu} command on a line by itself. + +A menu looks like this: + +@example +@group +@@menu +Larger Units of Text + +* Files:: All about handling files. +* Multiples: Buffers. Multiple buffers; editing + several files at once. +@@end menu +@end group +@end example + +In a menu, every line that begins with an @w{@samp{* }} is a @dfn{menu +entry}. (Note the space after the asterisk.) A line that does not +start with an @w{@samp{* }} may also appear in a menu. Such a line is +not a menu entry but is a menu comment line that appears in the Info +file. In the example above, the line @samp{Larger Units of Text} is a +menu comment line; the two lines starting with @w{@samp{* }} are menu +@cindex Spaces, in menus +entries. Space characters in a menu are preserved as-is; this allows +you to format the menu as you wish. + +@opindex accesskey@r{, in HTML output} +In the HTML output from @command{makeinfo}, the @code{accesskey} +attribute is used with the values @samp{1}@dots{}@samp{9} for the +first nine entries. This allows people using web browsers to follow +the first menu entries using (typically) @kbd{M-@var{digit}}, e.g., +@kbd{M-1} for the first entry. + + +@node Menu Parts +@section The Parts of a Menu +@cindex Parts of a menu +@cindex Menu parts +@cindex @code{@@menu} parts + +A menu entry has three parts, only the second of which is required: + +@enumerate +@item +The menu entry name (optional). + +@item +The name of the node (required). + +@item +A description of the item (optional). +@end enumerate + +The template for a generic menu entry looks like this (but see the +next section for one more possibility): + +@example +* @var{menu-entry-name}: @var{node-name}. @var{description} +@end example + +Follow the menu entry name with a single colon and follow the node name +with tab, comma, newline, or the two characters period and space +(@samp{. }). + +In Info, a user selects a node with the @kbd{m} (@code{Info-menu}) +command. The menu entry name is what the user types after the @kbd{m} +command. + +The third part of a menu entry is a descriptive phrase or sentence. +Menu entry names and node names are often short; the description +explains to the reader what the node is about. A useful description +complements the node name rather than repeats it. The description, +which is optional, can spread over two or more lines; if it does, some +authors prefer to indent the second line while others prefer to align it +with the first (and all others). It's up to you. + + +@node Less Cluttered Menu Entry +@section Less Cluttered Menu Entry +@cindex Two part menu entry +@cindex Double-colon menu entries +@cindex Menu entries with two colons +@cindex Less cluttered menu entry +@cindex Uncluttered menu entry + +When the menu entry name and node name are the same, you can write +the name immediately after the asterisk and space at the beginning of +the line and follow the name with two colons. + +@need 800 +For example, write + +@example +* Name:: @var{description} +@end example + +@need 800 +@noindent +instead of + +@example +* Name: Name. @var{description} +@end example + +You should indeed use the node name for the menu entry name whenever +possible, since it reduces visual clutter in the menu. + + +@node Menu Example +@section A Menu Example +@cindex Menu example +@cindex Example menu + +A menu looks like this in Texinfo:@refill + +@example +@group +@@menu +* menu entry name: Node name. A short description. +* Node name:: This form is preferred. +@@end menu +@end group +@end example + +@need 800 +@noindent +This produces: + +@example +@group +* menu: + +* menu entry name: Node name. A short description. +* Node name:: This form is preferred. +@end group +@end example + +@need 700 +Here is an example as you might see it in a Texinfo file:@refill + +@example +@group +@@menu +Larger Units of Text + +* Files:: All about handling files. +* Multiples: Buffers. Multiple buffers; editing + several files at once. +@@end menu +@end group +@end example + +@need 800 +@noindent +This produces: + +@example +@group +* menu: +Larger Units of Text + +* Files:: All about handling files. +* Multiples: Buffers. Multiple buffers; editing + several files at once. +@end group +@end example + +In this example, the menu has two entries. @samp{Files} is both a menu +entry name and the name of the node referred to by that name. +@samp{Multiples} is the menu entry name; it refers to the node named +@samp{Buffers}. The line @samp{Larger Units of Text} is a comment; it +appears in the menu, but is not an entry.@refill + +Since no file name is specified with either @samp{Files} or +@samp{Buffers}, they must be the names of nodes in the same Info file +(@pxref{Other Info Files, , Referring to Other Info Files}).@refill + +@node Other Info Files +@comment node-name, next, previous, up +@section Referring to Other Info Files +@cindex Referring to other Info files +@cindex Nodes in other Info files +@cindex Other Info files' nodes +@cindex Going to other Info files' nodes +@cindex Info; other files' nodes + +You can create a menu entry that enables a reader in Info to go to a +node in another Info file by writing the file name in parentheses just +before the node name. In this case, you should use the three-part menu +entry format, which saves the reader from having to type the file +name.@refill + +@need 800 +The format looks like this:@refill + +@example +@group +@@menu +* @var{first-entry-name}:(@var{filename})@var{nodename}. @var{description} +* @var{second-entry-name}:(@var{filename})@var{second-node}. @var{description} +@@end menu +@end group +@end example + +For example, to refer directly to the @samp{Outlining} and +@samp{Rebinding} nodes in the @cite{Emacs Manual}, you would write a +menu like this:@refill + +@example +@group +@@menu +* Outlining: (emacs)Outline Mode. The major mode for + editing outlines. +* Rebinding: (emacs)Rebinding. How to redefine the + meaning of a key. +@@end menu +@end group +@end example + +If you do not list the node name, but only name the file, then Info +presumes that you are referring to the `Top' node.@refill + +The @file{dir} file that contains the main menu for Info has menu +entries that list only file names. These take you directly to the `Top' +nodes of each Info document. (@xref{Installing an Info File}.) + +@need 700 +For example: + +@example +@group +* Info: (info). Documentation browsing system. +* Emacs: (emacs). The extensible, self-documenting + text editor. +@end group +@end example + +@noindent +(The @file{dir} top level directory for the Info system is an Info file, +not a Texinfo file, but a menu entry looks the same in both types of +file.)@refill + +The GNU Emacs Texinfo mode menu updating commands only work with nodes +within the current buffer, so you cannot use them to create menus that +refer to other files. You must write such menus by hand. + + +@node Cross References +@chapter Cross References +@cindex Making cross references +@cindex Cross references +@cindex References + +@dfn{Cross references} are used to refer the reader to other parts of the +same or different Texinfo files. In Texinfo, nodes and anchors are the +places to which cross references can refer. + +@menu +* References:: What cross references are for. +* Cross Reference Commands:: A summary of the different commands. +* Cross Reference Parts:: A cross reference has several parts. +* xref:: Begin a reference with `See' @dots{} +* Top Node Naming:: How to refer to the beginning of another file. +* ref:: A reference for the last part of a sentence. +* pxref:: How to write a parenthetical cross reference. +* inforef:: How to refer to an Info-only file. +* uref:: How to refer to a uniform resource locator. +* cite:: How to refer to books not in the Info system. +@end menu + +@node References +@section What References Are For + +Often, but not always, a printed document should be designed so that +it can be read sequentially. People tire of flipping back and forth +to find information that should be presented to them as they need +it.@refill + +However, in any document, some information will be too detailed for +the current context, or incidental to it; use cross references to +provide access to such information. Also, an online help system or a +reference manual is not like a novel; few read such documents in +sequence from beginning to end. Instead, people look up what they +need. For this reason, such creations should contain many cross +references to help readers find other information that they may not +have read.@refill + +In a printed manual, a cross reference results in a page reference, +unless it is to another manual altogether, in which case the cross +reference names that manual.@refill + +In Info, a cross reference results in an entry that you can follow +using the Info @samp{f} command. (@inforef{Help-Xref, Following +cross-references, info}.) + +The various cross reference commands use nodes (or anchors, +@pxref{anchor,,@code{@@anchor}}) to define cross reference locations. +This is evident in Info, in which a cross reference takes you to the +specified location. @TeX{} also uses nodes to define cross reference +locations, but the action is less obvious. When @TeX{} generates a DVI +file, it records each node's page number and uses the page numbers in making +references. Thus, if you are writing a manual that will only be +printed, and will not be used online, you must nonetheless write +@code{@@node} lines to name the places to which you make cross +references.@refill + +@need 800 +@node Cross Reference Commands +@comment node-name, next, previous, up +@section Different Cross Reference Commands +@cindex Different cross reference commands + +There are four different cross reference commands:@refill + +@table @code +@item @@xref +Used to start a sentence in the printed manual saying @w{`See @dots{}'} +or an Info cross-reference saying @samp{*Note @var{name}: @var{node}.}. + +@item @@ref +Used within or, more often, at the end of a sentence; same as +@code{@@xref} for Info; produces just the reference in the printed +manual without a preceding `See'.@refill + +@item @@pxref +Used within parentheses to make a reference that suits both an Info +file and a printed book. Starts with a lower case `see' within the +printed manual. (@samp{p} is for `parenthesis'.)@refill + +@item @@inforef +Used to make a reference to an Info file for which there is no printed +manual.@refill +@end table + +@noindent +(The @code{@@cite} command is used to make references to books and +manuals for which there is no corresponding Info file and, therefore, +no node to which to point. @xref{cite, , @code{@@cite}}.)@refill + +@node Cross Reference Parts +@comment node-name, next, previous, up +@section Parts of a Cross Reference +@cindex Cross reference parts +@cindex Parts of a cross reference + +A cross reference command requires only one argument, which is the +name of the node to which it refers. But a cross reference command +may contain up to four additional arguments. By using these +arguments, you can provide a cross reference name for Info, a topic +description or section title for the printed output, the name of a +different Info file, and the name of a different printed +manual.@refill + +Here is a simple cross reference example:@refill + +@example +@@xref@{Node name@}. +@end example + +@noindent +which produces + +@example +*Note Node name::. +@end example + +@noindent +and + +@quotation +See Section @var{nnn} [Node name], page @var{ppp}. +@end quotation + +@need 700 +Here is an example of a full five-part cross reference:@refill + +@example +@group +@@xref@{Node name, Cross Reference Name, Particular Topic, +info-file-name, A Printed Manual@}, for details. +@end group +@end example + +@noindent +which produces + +@example +*Note Cross Reference Name: (info-file-name)Node name, +for details. +@end example + +@noindent +in Info and + +@quotation +See section ``Particular Topic'' in @i{A Printed Manual}, for details. +@end quotation + +@noindent +in a printed book. + +The five possible arguments for a cross reference are:@refill + +@enumerate +@item +The node or anchor name (required). This is the location to which the +cross reference takes you. In a printed document, the location of the +node provides the page reference only for references within the same +document.@refill + +@item +The cross reference name for the Info reference, if it is to be +different from the node name or the topic description. If you +include this argument, it becomes the first part of the cross reference. +It is usually omitted; then the topic description (third argument) is +used if it was specified; if that was omitted as well, the node name +is used. + +@item +A topic description or section name. Often, this is the title of the +section. This is used as the name of the reference in the printed +manual. If omitted, the node name is used.@refill + +@item +The name of the Info file in which the reference is located, if it is +different from the current file. You need not include any @samp{.info} +suffix on the file name, since Info readers try appending it +automatically. + +@item +The name of a printed manual from a different Texinfo file.@refill +@end enumerate + +The template for a full five argument cross reference looks like +this:@refill + +@example +@group +@@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}, +@var{info-file-name}, @var{printed-manual-title}@}. +@end group +@end example + +Cross references with one, two, three, four, and five arguments are +described separately following the description of @code{@@xref}.@refill + +Write a node name in a cross reference in exactly the same way as in +the @code{@@node} line, including the same capitalization; otherwise, the +formatters may not find the reference.@refill + +You can write cross reference commands within a paragraph, but note +how Info and @TeX{} format the output of each of the various commands: +write @code{@@xref} at the beginning of a sentence; write +@code{@@pxref} only within parentheses, and so on.@refill + +@node xref +@comment node-name, next, previous, up +@section @code{@@xref} +@findex xref +@cindex Cross references using @code{@@xref} +@cindex References using @code{@@xref} + +The @code{@@xref} command generates a cross reference for the +beginning of a sentence. The Info formatting commands convert it into +an Info cross reference, which the Info @samp{f} command can use to +bring you directly to another node. The @TeX{} typesetting commands +convert it into a page reference, or a reference to another book or +manual.@refill + +@menu +* Reference Syntax:: What a reference looks like and requires. +* One Argument:: @code{@@xref} with one argument. +* Two Arguments:: @code{@@xref} with two arguments. +* Three Arguments:: @code{@@xref} with three arguments. +* Four and Five Arguments:: @code{@@xref} with four and five arguments. +@end menu + +@node Reference Syntax +@subsection What a Reference Looks Like and Requires + +Most often, an Info cross reference looks like this:@refill + +@example +*Note @var{node-name}::. +@end example + +@noindent +or like this + +@example +*Note @var{cross-reference-name}: @var{node-name}. +@end example + +@noindent +In @TeX{}, a cross reference looks like this: + +@quotation +See Section @var{section-number} [@var{node-name}], page @var{page}. +@end quotation + +@noindent +or like this + +@quotation +See Section @var{section-number} [@var{title-or-topic}], page @var{page}. +@end quotation + +The @code{@@xref} command does not generate a period or comma to end +the cross reference in either the Info file or the printed output. +You must write that period or comma yourself; otherwise, Info will not +recognize the end of the reference. (The @code{@@pxref} command works +differently. @xref{pxref, , @code{@@pxref}}.)@refill + +@quotation Caution +A period or comma @strong{must} follow the closing +brace of an @code{@@xref}. It is required to terminate the cross +reference. This period or comma will appear in the output, both in +the Info file and in the printed manual.@refill +@end quotation + +@code{@@xref} must refer to an Info node by name. Use @code{@@node} +to define the node (@pxref{Writing a Node}).@refill + +@code{@@xref} is followed by several arguments inside braces, separated by +commas. Whitespace before and after these commas is ignored.@refill + +A cross reference requires only the name of a node; but it may contain +up to four additional arguments. Each of these variations produces a +cross reference that looks somewhat different.@refill + +@quotation Note +Commas separate arguments in a cross reference; +avoid including them in the title or other part lest the formatters +mistake them for separators.@refill +@end quotation + +@node One Argument +@subsection @code{@@xref} with One Argument + +The simplest form of @code{@@xref} takes one argument, the name of +another node in the same Info file. The Info formatters produce +output that the Info readers can use to jump to the reference; @TeX{} +produces output that specifies the page and section number for you.@refill + +@need 700 +@noindent +For example, + +@example +@@xref@{Tropical Storms@}. +@end example + +@noindent +produces + +@example +*Note Tropical Storms::. +@end example + +@noindent +and + +@quotation +See Section 3.1 [Tropical Storms], page 24. +@end quotation + +@noindent +(Note that in the preceding example the closing brace is followed by a +period.)@refill + +You can write a clause after the cross reference, like this:@refill + +@example +@@xref@{Tropical Storms@}, for more info. +@end example + +@noindent +which produces + +@example +*Note Tropical Storms::, for more info. +@end example + +@noindent +and + +@quotation +See Section 3.1 [Tropical Storms], page 24, for more info. +@end quotation + +@noindent +(Note that in the preceding example the closing brace is followed by a +comma, and then by the clause, which is followed by a period.)@refill + +@node Two Arguments +@subsection @code{@@xref} with Two Arguments + +With two arguments, the second is used as the name of the Info cross +reference, while the first is still the name of the node to which the +cross reference points.@refill + +@need 750 +@noindent +The template is like this: + +@example +@@xref@{@var{node-name}, @var{cross-reference-name}@}. +@end example + +@need 700 +@noindent +For example, + +@example +@@xref@{Electrical Effects, Lightning@}. +@end example + +@noindent +produces: + +@example +*Note Lightning: Electrical Effects. +@end example + +@noindent +and + +@quotation +See Section 5.2 [Electrical Effects], page 57. +@end quotation + +@noindent +(Note that in the preceding example the closing brace is followed by a +period; and that the node name is printed, not the cross reference name.) + +You can write a clause after the cross reference, like this:@refill + +@example +@@xref@{Electrical Effects, Lightning@}, for more info. +@end example + +@noindent +which produces +@example +*Note Lightning: Electrical Effects, for more info. +@end example + +@noindent +and + +@quotation +See Section 5.2 [Electrical Effects], page 57, for more info. +@end quotation + +@noindent +(Note that in the preceding example the closing brace is followed by a +comma, and then by the clause, which is followed by a period.)@refill + +@node Three Arguments +@subsection @code{@@xref} with Three Arguments + +A third argument replaces the node name in the @TeX{} output. The third +argument should be the name of the section in the printed output, or +else state the topic discussed by that section. Often, you will want to +use initial upper case letters so it will be easier to read when the +reference is printed. Use a third argument when the node name is +unsuitable because of syntax or meaning.@refill + +Remember to avoid placing a comma within the title or topic section of +a cross reference, or within any other section. The formatters divide +cross references into arguments according to the commas; a comma +within a title or other section will divide it into two arguments. In +a reference, you need to write a title such as ``Clouds, Mist, and +Fog'' without the commas.@refill + +Also, remember to write a comma or period after the closing brace of an +@code{@@xref} to terminate the cross reference. In the following +examples, a clause follows a terminating comma.@refill + + +@need 750 +@noindent +The template is like this: + +@example +@group +@@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}@}. +@end group +@end example + +@need 700 +@noindent +For example, + +@example +@group +@@xref@{Electrical Effects, Lightning, Thunder and Lightning@}, +for details. +@end group +@end example + +@noindent +produces + +@example +*Note Lightning: Electrical Effects, for details. +@end example + +@noindent +and + +@quotation +See Section 5.2 [Thunder and Lightning], page 57, for details. +@end quotation + +If a third argument is given and the second one is empty, then the +third argument serves both. (Note how two commas, side by side, mark +the empty second argument.)@refill + +@example +@group +@@xref@{Electrical Effects, , Thunder and Lightning@}, +for details. +@end group +@end example + +@noindent +produces + +@example +*Note Thunder and Lightning: Electrical Effects, for details. +@end example + +@noindent +and + +@quotation +See Section 5.2 [Thunder and Lightning], page 57, for details. +@end quotation + +As a practical matter, it is often best to write cross references with +just the first argument if the node name and the section title are the +same, and with the first and third arguments if the node name and title +are different.@refill + +Here are several examples from @cite{The GNU Awk User's Guide}:@refill + +@smallexample +@@xref@{Sample Program@}. +@@xref@{Glossary@}. +@@xref@{Case-sensitivity, ,Case-sensitivity in Matching@}. +@@xref@{Close Output, , Closing Output Files and Pipes@}, + for more information. +@@xref@{Regexp, , Regular Expressions as Patterns@}. +@end smallexample + +@node Four and Five Arguments +@subsection @code{@@xref} with Four and Five Arguments + +In a cross reference, a fourth argument specifies the name of another +Info file, different from the file in which the reference appears, and +a fifth argument specifies its title as a printed manual.@refill + +Remember that a comma or period must follow the closing brace of an +@code{@@xref} command to terminate the cross reference. In the +following examples, a clause follows a terminating comma.@refill + +@need 800 +@noindent +The template is: + +@example +@group +@@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}, +@var{info-file-name}, @var{printed-manual-title}@}. +@end group +@end example + +@need 700 +@noindent +For example, + +@example +@@xref@{Electrical Effects, Lightning, Thunder and Lightning, +weather, An Introduction to Meteorology@}, for details. +@end example + +@noindent +produces + +@example +*Note Lightning: (weather)Electrical Effects, for details. +@end example + +@noindent +The name of the Info file is enclosed in parentheses and precedes +the name of the node. + +@noindent +In a printed manual, the reference looks like this:@refill + +@quotation +See section ``Thunder and Lightning'' in @i{An Introduction to +Meteorology}, for details. +@end quotation + +@noindent +The title of the printed manual is typeset in italics; and the +reference lacks a page number since @TeX{} cannot know to which page a +reference refers when that reference is to another manual.@refill + +Often, you will leave out the second argument when you use the long +version of @code{@@xref}. In this case, the third argument, the topic +description, will be used as the cross reference name in Info.@refill + +@noindent +The template looks like this: + +@example +@@xref@{@var{node-name}, , @var{title-or-topic}, @var{info-file-name}, +@var{printed-manual-title}@}, for details. +@end example + +@noindent +which produces + +@example +*Note @var{title-or-topic}: (@var{info-file-name})@var{node-name}, for details. +@end example + +@noindent +and + +@quotation +See section @var{title-or-topic} in @var{printed-manual-title}, for details. +@end quotation + +@need 700 +@noindent +For example, + +@example +@@xref@{Electrical Effects, , Thunder and Lightning, +weather, An Introduction to Meteorology@}, for details. +@end example + +@noindent +produces + +@example +@group +*Note Thunder and Lightning: (weather)Electrical Effects, +for details. +@end group +@end example + +@noindent +and + +@quotation +See section ``Thunder and Lightning'' in @i{An Introduction to +Meteorology}, for details. +@end quotation + +On rare occasions, you may want to refer to another Info file that +is within a single printed manual---when multiple Texinfo files are +incorporated into the same @TeX{} run but make separate Info files. +In this case, you need to specify only the fourth argument, and not +the fifth.@refill + +@node Top Node Naming +@section Naming a `Top' Node +@cindex Naming a `Top' Node in references +@cindex @samp{@r{Top}} node naming for references + +In a cross reference, you must always name a node. This means that in +order to refer to a whole manual, you must identify the `Top' node by +writing it as the first argument to the @code{@@xref} command. (This +is different from the way you write a menu entry; see @ref{Other Info +Files, , Referring to Other Info Files}.) At the same time, to +provide a meaningful section topic or title in the printed cross +reference (instead of the word `Top'), you must write an appropriate +entry for the third argument to the @code{@@xref} command. +@refill + +@noindent +Thus, to make a cross reference to @cite{The GNU Make Manual}, +write:@refill + +@example +@@xref@{Top, , Overview, make, The GNU Make Manual@}. +@end example + +@noindent +which produces + +@example +*Note Overview: (make)Top. +@end example + +@noindent +and + +@quotation +See section ``Overview'' in @i{The GNU Make Manual}. +@end quotation + +@noindent +In this example, @samp{Top} is the name of the first node, and +@samp{Overview} is the name of the first section of the manual. + + +@node ref +@section @code{@@ref} +@cindex Cross references using @code{@@ref} +@cindex References using @code{@@ref} +@findex ref + +@code{@@ref} is nearly the same as @code{@@xref} except that it does +not generate a `See' in the printed output, just the reference itself. +This makes it useful as the last part of a sentence. + +@noindent For example, + +@cindex Hurricanes +@example +For more information, @@pxref@{This@}, and @@ref@{That@}. +@end example + +@noindent produces in Info: + +@example +For more information, *note This::, and *note That::. +@end example + +@noindent and in printed output: + +@quotation +For more information, see Section 1.1 [This], page 1, +and Section 1.2 [That], page 2. +@end quotation + +The @code{@@ref} command sometimes tempts writers to express +themselves in a manner that is suitable for a printed manual but looks +awkward in the Info format. Bear in mind that your audience will be +using both the printed and the Info format. For example: + +@cindex Sea surges +@example +Sea surges are described in @@ref@{Hurricanes@}. +@end example + +@noindent looks ok in the printed output: + +@quotation +Sea surges are described in Section 6.7 [Hurricanes], page 72. +@end quotation + +@noindent but is awkward to read in Info, ``note'' being a verb: + +@example +Sea surges are described in *note Hurricanes::. +@end example + +You should write a period or comma immediately after an @code{@@ref} +command with two or more arguments. If there is no such following +punctuation, @command{makeinfo} will generate a (grammatically +incorrect) period in the Info output; otherwise, the cross-reference +would fail completely, due to the current syntax of Info format. + +In general, it is best to use @code{@@ref} only when you need some +word other than ``see'' to precede the reference. When ``see'' (or +``See'') is ok, @code{@@xref} and @code{@@pxref} are preferable. + + +@node pxref +@section @code{@@pxref} +@cindex Cross references using @code{@@pxref} +@cindex References using @code{@@pxref} +@findex pxref + +The parenthetical reference command, @code{@@pxref}, is nearly the +same as @code{@@xref}, but it is best used at the end of a sentence or +before a closing parenthesis. The command differs from @code{@@xref} +in two ways: + +@enumerate +@item +@TeX{} typesets the reference for the printed manual with a lower case +`see' rather than an upper case `See'. + +@item +The Info formatting commands automatically end the reference with a +closing colon or period, if necessary. +@end enumerate + +@code{@@pxref} is designed so that the output looks right and works +right at the end of a sentence or parenthetical phrase, both in +printed output and in an Info file. In a printed manual, a closing +comma or period should not follow a cross reference within +parentheses; such punctuation is wrong. But in an Info file, suitable +closing punctuation must follow the cross reference so Info can +recognize its end. @code{@@pxref} spares you the need to use +complicated methods to put a terminator into one form of the output +and not the other. + +@noindent +With one argument, a parenthetical cross reference looks like this: + +@cindex Flooding +@example +@dots{} storms cause flooding (@@pxref@{Hurricanes@}) @dots{} +@end example + +@need 800 +@noindent +which produces + +@example +@group +@dots{} storms cause flooding (*note Hurricanes::) @dots{} +@end group +@end example + +@noindent +and + +@quotation +@dots{} storms cause flooding (see Section 6.7 [Hurricanes], page 72) @dots{} +@end quotation + +With two arguments, a parenthetical cross reference has this template: + +@example +@dots{} (@@pxref@{@var{node-name}, @var{cross-reference-name}@}) @dots{} +@end example + +@noindent +which produces + +@example +@dots{} (*note @var{cross-reference-name}: @var{node-name}.) @dots{} +@end example + +@noindent +and + +@quotation +@dots{} (see Section @var{nnn} [@var{node-name}], page @var{ppp}) @dots{} +@end quotation + +@code{@@pxref} can be used with up to five arguments, just like +@code{@@xref} (@pxref{xref, , @code{@@xref}}). + +In past versions of Texinfo, it was not allowed to write punctuation +after a @code{@@pxref}, so it could be used @emph{only} before a right +parenthesis. This is no longer the case, so now it can be used (for +example) at the end of a sentence, where a lowercase ``see'' works +best. For instance: + +@example +@dots{} For more information, @@pxref@{More@}. +@end example + +@noindent +which outputs (in Info): + +@example +@dots{} For more information, *note More::. +@end example + +@noindent +This works fine. @code{@@pxref} should only be followed by a comma, +period, or right parenthesis; in other cases, @command{makeinfo} has +to insert a period to make the cross-reference work correctly in Info, +and that period looks wrong. + +As a matter of general style, @code{@@pxref} is best used at the ends +of sentences. Although it technically works in the middle of a +sentence, that location breaks up the flow of reading. + + +@node inforef +@section @code{@@inforef} +@cindex Cross references using @code{@@inforef} +@cindex References using @code{@@inforef} +@findex inforef + +@code{@@inforef} is used for making cross references to Info +documents---even from a printed manual. This might be because you +want to refer to conditional @code{@@ifinfo} text +(@pxref{Conditionals}), or because printed output is not available +(perhaps because there is no Texinfo source), among other +possibilities. + +The command takes either two or three arguments, in the following +order:@refill + +@enumerate +@item +The node name. + +@item +The cross reference name (optional). + +@item +The Info file name. +@end enumerate + +@noindent +Separate the arguments with commas, as with @code{@@xref}. Also, you +must terminate the reference with a comma or period after the +@samp{@}}, as you do with @code{@@xref}.@refill + +@noindent +The template is: + +@example +@@inforef@{@var{node-name}, @var{cross-reference-name}, @var{info-file-name}@}, +@end example + +@need 800 +@noindent +For example, + +@example +@group +@@inforef@{Advanced, Advanced Info commands, info@}, +for more information. +@end group +@end example + +@need 800 +@noindent +produces (in Info): + +@example +@group +*Note Advanced Info commands: (info)Advanced, +for more information. +@end group +@end example + +@need 800 +@noindent +and (in the printed output): + +@quotation +See Info file @file{info}, node @samp{Advanced}, for more information. +@end quotation + +(This particular example is not realistic, since the Info manual is +written in Texinfo, so all formats are available.) + +The converse of @code{@@inforef} is @code{@@cite}, which is used to +refer to printed works for which no Info form exists. @xref{cite, , +@code{@@cite}}. + + +@node uref +@section @code{@@url}, @code{@@uref@{@var{url}[, @var{text}][, @var{replacement}]@}} +@findex uref +@cindex Uniform resource locator, referring to +@cindex URL, referring to + +@cindex @code{href}, producing HTML +@code{@@uref} produces a reference to a uniform resource locator (url). +It takes one mandatory argument, the url, and two optional arguments +which control the text that is displayed. In HTML output, @code{@@uref} +produces a link you can follow. + +@code{@@url} is a synonym for @code{@@uref}. Originally, @code{@@url} +had the meaning of @code{@@indicateurl} +(@pxref{indicateurl,,@code{@@indicateurl}}), but in actual practice it +was misused the vast majority of the time. So we've changed the +meaning. + +The second argument, if specified, is the text to display (the default +is the url itself); in Info and DVI output, but not in HTML output, the +url is also output. + +@cindex Man page, reference to +The third argument, if specified, is the text to display, but in this +case the url is @emph{not} output in any format. This is useful when +the text is already sufficiently referential, as in a man page. If +the third argument is given, the second argument is ignored. + +If the url is long enough to cause problems with line breaking, you +may find it useful to insert @code{@@/} at places where a line break +would be acceptable (after @samp{/} characters, for instance). This +tells @TeX{} to allow (but not force) a line break at those places. +@xref{Line Breaks}. + +Here is an example of the simple one argument form, where the url is +both the target and the text of the link: + +@example +The official GNU ftp site is @@uref@{ftp://ftp.gnu.org/gnu@}. +@end example + +@noindent produces: +@display +The official GNU ftp site is @uref{ftp://ftp.gnu.org/gnu}. +@end display + + +An example of the two-argument form: +@example +The official @@uref@{ftp://ftp.gnu.org/gnu, GNU ftp site@} +holds programs and texts. +@end example + +@noindent produces: +@display +The official @uref{ftp://ftp.gnu.org/gnu, GNU ftp site} +holds programs and texts. +@end display + +@noindent that is, the Info output is this: +@example +The official GNU ftp site (ftp://ftp.gnu.org/gnu) +holds programs and texts. +@end example + +@noindent and the HTML output is this: +@example +The official <a href="ftp://ftp.gnu.org/gnu">GNU ftp site</a> +holds programs and texts. +@end example + + +An example of the three-argument form: +@example +The @@uref@{/man.cgi/1/ls,,ls@} program @dots{} +@end example + +@noindent produces: +@display +The @uref{/man.cgi/1/ls,,ls} program @dots{} +@end display + +@noindent but with HTML: +@example +The <a href="/man.cgi/1/ls">ls</a> program @dots{} +@end example + +To merely indicate a url without creating a link people can follow, use +@code{@@indicateurl} (@pxref{indicateurl, @code{@@indicateurl}}). + +Some people prefer to display url's in the unambiguous format: + +@display +<URL:http://@var{host}/@var{path}> +@end display + +@noindent +@cindex <URL: convention, not used +You can use this form in the input file if you wish. We feel it's not +necessary to include the @samp{<URL:} and @samp{>} in the output, +since any software that tries to detect url's in text already has to +detect them without the @samp{<URL:} to be useful. + + +@node cite +@section @code{@@cite}@{@var{reference}@} +@findex cite + +Use the @code{@@cite} command for the name of a book that lacks a +companion Info file. The command produces italics in the printed +manual, and quotation marks in the Info file. + +If a book is written in Texinfo, it is better to use a cross reference +command since a reader can easily follow such a reference in Info. +@xref{xref, , @code{@@xref}}. + + +@node Marking Text +@chapter Marking Words and Phrases +@cindex Paragraph, marking text within +@cindex Marking words and phrases +@cindex Words and phrases, marking them +@cindex Marking text within a paragraph +@cindex Text, marking up + +In Texinfo, you can mark words and phrases in a variety of ways. +The Texinfo formatters use this information to determine how to +highlight the text. +You can specify, for example, whether a word or phrase is a +defining occurrence, a metasyntactic variable, or a symbol used in a +program. Also, you can emphasize text, in several different ways. + +@menu +* Indicating:: How to indicate definitions, files, etc. +* Emphasis:: How to emphasize text. +@end menu + + +@node Indicating +@section Indicating Definitions, Commands, etc. +@cindex Highlighting text +@cindex Indicating commands, definitions, etc. + +Texinfo has commands for indicating just what kind of object a piece of +text refers to. For example, metasyntactic variables are marked by +@code{@@var}, and code by @code{@@code}. Since the pieces of text are +labelled by commands that tell what kind of object they are, it is easy +to change the way the Texinfo formatters prepare such text. (Texinfo is +an @emph{intentional} formatting language rather than a @emph{typesetting} +formatting language.)@refill + +For example, in a printed manual, +code is usually illustrated in a typewriter font; +@code{@@code} tells @TeX{} to typeset this text in this font. But it +would be easy to change the way @TeX{} highlights code to use another +font, and this change would not affect how keystroke examples are +highlighted. If straight typesetting commands were used in the body +of the file and you wanted to make a change, you would need to check +every single occurrence to make sure that you were changing code and +not something else that should not be changed.@refill + +@menu +* Useful Highlighting:: Highlighting provides useful information. +* code:: Indicating program code. +* kbd:: Showing keyboard input. +* key:: Specifying keys. +* samp:: Indicating a literal sequence of characters. +* verb:: Indicating a verbatim sequence of characters. +* var:: Indicating metasyntactic variables. +* env:: Indicating environment variables. +* file:: Indicating file names. +* command:: Indicating command names. +* option:: Indicating option names. +* dfn:: Specifying definitions. +* abbr:: Indicating abbreviations. +* acronym:: Indicating acronyms. +* indicateurl:: Indicating an example URL. +* email:: Indicating an electronic mail address. +@end menu + + +@node Useful Highlighting +@subsection Highlighting Commands are Useful + +The highlighting commands can be used to extract useful information +from the file, such as lists of functions or file names. It is +possible, for example, to write a program in Emacs Lisp (or a keyboard +macro) to insert an index entry after every paragraph that contains +words or phrases marked by a specified command. You could do this to +construct an index of functions if you had not already made the +entries.@refill + +The commands serve a variety of purposes:@refill + +@table @code +@item @@code@{@var{sample-code}@} +Indicate text that is a literal example of a piece of a program. +@xref{code,,@code{@@code}}. + +@item @@kbd@{@var{keyboard-characters}@} +Indicate keyboard input. +@xref{kbd,,@code{@@kbd}}. + +@item @@key@{@var{key-name}@} +Indicate the conventional name for a key on a keyboard. +@xref{key,,@code{@@key}}. + +@item @@samp@{@var{text}@} +Indicate text that is a literal example of a sequence of characters. +@xref{samp,,@code{@@samp}}. + +@item @@verb@{@var{text}@} +Write a verbatim sequence of characters. +@xref{verb,,@code{@@verb}}. + +@item @@var@{@var{metasyntactic-variable}@} +Indicate a metasyntactic variable. +@xref{var,,@code{@@var}}. + +@item @@env@{@var{environment-variable}@} +Indicate an environment variable. +@xref{env,,@code{@@env}}. + +@item @@file@{@var{file-name}@} +Indicate the name of a file. +@xref{file,,@code{@@file}}. + +@item @@command@{@var{command-name}@} +Indicate the name of a command. +@xref{command,,@code{@@command}}. + +@item @@option@{@var{option}@} +Indicate a command-line option. +@xref{option,,@code{@@option}}. + +@item @@dfn@{@var{term}@} +Indicate the introductory or defining use of a term. +@xref{dfn,,@code{@@dfn}}. + +@item @@cite@{@var{reference}@} +Indicate the name of a book. +@xref{cite,,@code{@@cite}}. + +@item @@abbr@{@var{abbreviation}@} +Indicate an abbreviation, such as `Comput.'. + +@item @@acronym@{@var{acronym}@} +Indicate an acronym. +@xref{acronym,,@code{@@acronym}}. + +@item @@indicateurl@{@var{uniform-resource-locator}@} +Indicate an example (that is, nonfunctional) uniform resource locator. +@xref{indicateurl,,@code{@@indicateurl}}. (Use @code{@@url} +(@pxref{uref,,@code{@@url}}) for live url's.) + +@item @@email@{@var{email-address}[, @var{displayed-text}]@} +Indicate an electronic mail address. +@xref{email,,@code{@@email}}. + +@ignore +@item @@ctrl@{@var{ctrl-char}@} +Use for an ASCII control character. +@end ignore +@end table + + +@node code +@subsection @code{@@code}@{@var{sample-code}@} +@findex code + +@cindex Syntactic tokens, indicating +Use the @code{@@code} command to indicate text that is a piece of a +program and which consists of entire syntactic tokens. Enclose the +text in braces. + +@cindex Expressions in a program, indicating +@cindex Keywords, indicating +@cindex Reserved words, indicating +Thus, you should use @code{@@code} for an expression in a program, for +the name of a variable or function used in a program, or for a +keyword in a programming language. + +Use @code{@@code} for command names in languages that resemble +programming languages, such as Texinfo. For example, @code{@@code} and +@code{@@samp} are produced by writing @samp{@@code@{@@@@code@}} and +@samp{@@code@{@@@@samp@}} in the Texinfo source, respectively. + +@cindex Case, not altering in @code{@@code} +It is incorrect to alter the case of a word inside an @code{@@code} +command when it appears at the beginning of a sentence. Most computer +languages are case sensitive. In C, for example, @code{Printf} is +different from the identifier @code{printf}, and most likely is a +misspelling of it. Even in languages which are not case sensitive, it +is confusing to a human reader to see identifiers spelled in different +ways. Pick one spelling and always use that. If you do not want to +start a sentence with a command name written all in lower case, you +should rearrange the sentence. + +In the printed manual, @code{@@code} causes @TeX{} to typeset the +argument in a typewriter face. In the Info file, it causes the Info +formatting commands to use single quotation marks around the text. +For example, + +@example +The function returns @@code@{nil@}. +@end example + +@noindent +produces this: + +@quotation +The function returns @code{nil}. +@end quotation + +@iftex +@noindent +and this in the Info file: +@example +The function returns `nil'. +@end example +@end iftex + +Here are some cases for which it is preferable @emph{not} to use @code{@@code}: + +@itemize @bullet +@item +For shell command names such as @command{ls} (use @code{@@command}). + +@item +For shell options such as @samp{-c} when such options stand alone (use +@code{@@option}). + +@item +Also, an entire shell command often looks better if written using +@code{@@samp} rather than @code{@@code}. In this case, the rule is to +choose the more pleasing format. + +@item +For environment variable such as @env{TEXINPUTS} (use @code{@@env}). + +@item +For a string of characters shorter than a syntactic token. For example, +if you are writing about @samp{goto-ch}, which is just a part of the +name for the @code{goto-char} Emacs Lisp function, you should use +@code{@@samp}. + +@item +In general, when writing about the characters used in a token; for +example, do not use @code{@@code} when you are explaining what letters +or printable symbols can be used in the names of functions. (Use +@code{@@samp}.) Also, you should not use @code{@@code} to mark text +that is considered input to programs unless the input is written in a +language that is like a programming language. For example, you should +not use @code{@@code} for the keystroke commands of GNU Emacs (use +@code{@@kbd} instead) although you may use @code{@@code} for the names +of the Emacs Lisp functions that the keystroke commands invoke. + +@end itemize + +Since @code{@@command}, @code{@@option}, and @code{@@env} were +introduced relatively recently, it is acceptable to use @code{@@code} or +@code{@@samp} for command names, options, and environment variables. +The new commands allow you to express the markup more precisely, but +there is no real harm in using the older commands, and of course the +long-standing manuals do so. + +Ordinarily, @TeX{} will consider breaking lines at @samp{-} and +@samp{_} characters within @code{@@code} and related commands. This +can be controlled with @code{@@allowcodebreaks} +(@pxref{allowcodebreaks,,@code{@@allowcodebreaks}}). + + +@node kbd +@subsection @code{@@kbd}@{@var{keyboard-characters}@} +@findex kbd +@cindex Keyboard input + +Use the @code{@@kbd} command for characters of input to be typed by +users. For example, to refer to the characters @kbd{M-a}, write: + +@example +@@kbd@{M-a@} +@end example + +@noindent +and to refer to the characters @kbd{M-x shell}, write: + +@example +@@kbd@{M-x shell@} +@end example + +@cindex User input +@cindex Slanted typewriter font, for @code{@@kbd} +By default, the @code{@@kbd} command produces a different font +(slanted typewriter instead of normal typewriter) in the printed +manual, so users can distinguish the characters that they are supposed +to type from those that the computer outputs. + +In Info output, @code{@@kbd} is usually the same as @code{@@code}, +producing `quotes' around its argument. However, in typewriter-like +contexts such as the @code{@@example} environment (@pxref{example}) +and @code{@@code} command itself, the quotes are omitted, since Info +format cannot use distinguishing fonts. + +@findex kbdinputstyle +Since the usage of @code{@@kbd} varies from manual to manual, you can +control the font switching with the @code{@@kbdinputstyle} command. +This command has no effect on Info output. Write this command at the +beginning of a line with a single word as an argument, one of the +following: + +@vindex distinct@r{, value for @code{@@kbdinputstyle}} +@vindex example@r{, value for @code{@@kbdinputstyle}} +@vindex code@r{, value for @code{@@kbdinputstyle}} +@table @samp +@item code +Always use the same font for @code{@@kbd} as @code{@@code}. +@item example +Use the distinguishing font for @code{@@kbd} only in @code{@@example} +and similar environments. +@item distinct +(the default) Always use the distinguishing font for @code{@@kbd}. +@end table + +You can embed another @@-command inside the braces of an @code{@@kbd} +command. Here, for example, is the way to describe a command that +would be described more verbosely as ``press the @samp{r} key and then +press the @key{RETURN} key'': + +@example +@@kbd@{r @@key@{RET@}@} +@end example + +@noindent +This produces: @kbd{r @key{RET}}. (The present manual uses the +default for @code{@@kbdinputstyle}.) + +You also use the @code{@@kbd} command if you are spelling out the letters +you type; for example: + +@example +To give the @@code@{logout@} command, +type the characters @@kbd@{l o g o u t @@key@{RET@}@}. +@end example + +@noindent +This produces: + +@quotation +To give the @code{logout} command, +type the characters @kbd{l o g o u t @key{RET}}. +@end quotation + +(Also, this example shows that you can add spaces for clarity. If you +explicitly want to mention a space character as one of the characters of +input, write @kbd{@@key@{SPC@}} for it.)@refill + + +@node key +@subsection @code{@@key}@{@var{key-name}@} +@findex key + +Use the @code{@@key} command for the conventional name for a key on a +keyboard, as in:@refill + +@example +@@key@{RET@} +@end example + +You can use the @code{@@key} command within the argument of an +@code{@@kbd} command when the sequence of characters to be typed +includes one or more keys that are described by name.@refill + +For example, to produce @kbd{C-x @key{ESC}} and @kbd{M-@key{TAB}} you +would type: + +@example +@@kbd@{C-x @@key@{ESC@}@} +@@kbd@{M-@@key@{TAB@}@} +@end example + +Here is a list of the recommended names for keys: +@cindex Recommended names for keys +@cindex Keys, recommended names +@cindex Names recommended for keys +@cindex Abbreviations for keys + +@quotation +@table @t +@item SPC +Space +@item RET +Return +@item LFD +Linefeed (however, since most keyboards nowadays do not have a Linefeed key, +it might be better to call this character @kbd{C-j}) +@item TAB +Tab +@item BS +Backspace +@item ESC +Escape +@item DELETE +Delete +@item SHIFT +Shift +@item CTRL +Control +@item META +Meta +@end table +@end quotation + +@cindex META key +There are subtleties to handling words like `meta' or `ctrl' that are +names of modifier keys. When mentioning a character in which the +modifier key is used, such as @kbd{Meta-a}, use the @code{@@kbd} command +alone; do not use the @code{@@key} command; but when you are referring +to the modifier key in isolation, use the @code{@@key} command. For +example, write @samp{@@kbd@{Meta-a@}} to produce @kbd{Meta-a} and +@samp{@@key@{META@}} to produce @key{META}. + +As a convention in GNU manuals, @code{@@key} should not be used in +index entries. + + +@node samp +@subsection @code{@@samp}@{@var{text}@} +@findex samp + +Use the @code{@@samp} command to indicate text that is a literal example +or `sample' of a sequence of characters in a file, string, pattern, etc. +Enclose the text in braces. The argument appears within single +quotation marks in both the Info file and the printed manual; in +addition, it is printed in a fixed-width font.@refill + +@example +To match @@samp@{foo@} at the end of the line, +use the regexp @@samp@{foo$@}. +@end example + +@noindent +produces + +@quotation +To match @samp{foo} at the end of the line, use the regexp +@samp{foo$}.@refill +@end quotation + +Any time you are referring to single characters, you should use +@code{@@samp} unless @code{@@kbd} or @code{@@key} is more appropriate. +Also, you may use @code{@@samp} for entire statements in C and for entire +shell commands---in this case, @code{@@samp} often looks better than +@code{@@code}. Basically, @code{@@samp} is a catchall for whatever is +not covered by @code{@@code}, @code{@@kbd}, or @code{@@key}.@refill + +Only include punctuation marks within braces if they are part of the +string you are specifying. Write punctuation marks outside the braces +if those punctuation marks are part of the English text that surrounds +the string. In the following sentence, for example, the commas and +period are outside of the braces:@refill + +@example +@group +In English, the vowels are @@samp@{a@}, @@samp@{e@}, +@@samp@{i@}, @@samp@{o@}, @@samp@{u@}, and sometimes +@@samp@{y@}. +@end group +@end example + +@noindent +This produces: + +@quotation +In English, the vowels are @samp{a}, @samp{e}, +@samp{i}, @samp{o}, @samp{u}, and sometimes +@samp{y}. +@end quotation + + +@node verb +@subsection @code{@@verb}@{<char>@var{text}<char>@} +@findex verb +@cindex Verbatim in-line text + +@cindex Delimiter character, for verbatim +Use the @code{@@verb} command to print a verbatim sequence of +characters. + +Like @LaTeX{}'s @code{\verb} command, the verbatim text can be quoted using +any unique delimiter character. Enclose the verbatim text, including the +delimiters, in braces. Text is printed in a fixed-width font: + +@example +How many @@verb@{|@@|@}-escapes does one need to print this +@@verb@{.@@a @@b @@c.@} string or @@verb@{+@@'e@?`@!`@{@}\+@} this? +@end example + +@noindent +produces + +@example +How many @verb{|@|}-escapes does one need to print this +@verb{.@a @b @c.} string or these @verb{+@'e?`{}!`\+} this? +@end example + +This is in contrast to @code{@@samp} (see the previous section), +@code{@@code}, and similar commands; in those cases, the argument is +normal Texinfo text, where the three characters @code{@@@{@}} are +special. With @code{@@verb}, nothing is special except the delimiter +character you choose. + +It is not reliable to use @code{@@verb} inside other Texinfo +constructs. In particular, it does not work to use @code{@@verb} in +anything related to cross-referencing, such as section titles or +figure captions. + + +@node var +@subsection @code{@@var}@{@var{metasyntactic-variable}@} +@findex var + +Use the @code{@@var} command to indicate metasyntactic variables. A +@dfn{metasyntactic variable} is something that stands for another piece of +text. For example, you should use a metasyntactic variable in the +documentation of a function to describe the arguments that are passed +to that function.@refill + +Do not use @code{@@var} for the names of particular variables in +programming languages. These are specific names from a program, so +@code{@@code} is correct for them (@pxref{code}). For example, the +Emacs Lisp variable @code{texinfo-tex-command} is not a metasyntactic +variable; it is properly formatted using @code{@@code}. + +Do not use @code{@@var} for environment variables either; @code{@@env} +is correct for them (see the next section). + +The effect of @code{@@var} in the Info file is to change the case of the +argument to all upper case. In the printed manual and HTML output, the +argument is printed in slanted type. + +@need 700 +For example, + +@example +To delete file @@var@{filename@}, +type @@samp@{rm @@var@{filename@}@}. +@end example + +@noindent +produces + +@quotation +To delete file @var{filename}, type @samp{rm @var{filename}}. +@end quotation + +@noindent +(Note that @code{@@var} may appear inside @code{@@code}, +@code{@@samp}, @code{@@file}, etc.)@refill + +Write a metasyntactic variable all in lower case without spaces, and +use hyphens to make it more readable. Thus, the Texinfo source for +the illustration of how to begin a Texinfo manual looks like +this:@refill + +@example +@group +\input texinfo +@@@@setfilename @@var@{info-file-name@} +@@@@settitle @@var@{name-of-manual@} +@end group +@end example + +@noindent +This produces: + +@example +@group +\input texinfo +@@setfilename @var{info-file-name} +@@settitle @var{name-of-manual} +@end group +@end example + +In some documentation styles, metasyntactic variables are shown with +angle brackets, for example:@refill + +@example +@dots{}, type rm <filename> +@end example + +@noindent +However, that is not the style that Texinfo uses. (You can, of +course, modify the sources to @file{texinfo.tex} and the Info formatting commands +to output the @code{<@dots{}>} format if you wish.)@refill + + +@node env +@subsection @code{@@env}@{@var{environment-variable}@} +@findex env + +Use the @code{@@env} command to indicate environment variables, as used +by many operating systems, including GNU. Do not use it for +metasyntactic variables; use @code{@@var} instead (see the previous +section). + +@code{@@env} is equivalent to @code{@@code} in its effects. +For example: + +@example +The @@env@{PATH@} environment variable @dots{} +@end example +@noindent produces +@quotation +The @env{PATH} environment variable @dots{} +@end quotation + + +@node file +@subsection @code{@@file}@{@var{file-name}@} +@findex file + +Use the @code{@@file} command to indicate text that is the name of a +file, buffer, or directory, or is the name of a node in Info. You can +also use the command for file name suffixes. Do not use @code{@@file} +for symbols in a programming language; use @code{@@code}. + +Currently, @code{@@file} is equivalent to @code{@@samp} in its effects. +For example,@refill + +@example +The @@file@{.el@} files are in +the @@file@{/usr/local/emacs/lisp@} directory. +@end example + +@noindent +produces + +@quotation +The @file{.el} files are in +the @file{/usr/local/emacs/lisp} directory. +@end quotation + + +@node command +@subsection @code{@@command}@{@var{command-name}@} +@findex command +@cindex Command names, indicating +@cindex Program names, indicating + +Use the @code{@@commannd} command to indicate command names, such as +@command{ls} or @command{cc}. + +@code{@@command} is equivalent to @code{@@code} in its effects. +For example: + +@example +The command @@command@{ls@} lists directory contents. +@end example +@noindent produces +@quotation +The command @command{ls} lists directory contents. +@end quotation + +You should write the name of a program in the ordinary text font, rather +than using @code{@@command}, if you regard it as a new English word, +such as `Emacs' or `Bison'. + +When writing an entire shell command invocation, as in @samp{ls -l}, +you should use either @code{@@samp} or @code{@@code} at your discretion. + + +@node option +@subsection @code{@@option}@{@var{option-name}@} +@findex option + +Use the @code{@@option} command to indicate a command-line option; for +example, @option{-l} or @option{--version} or +@option{--output=@var{filename}}. + +@code{@@option} is equivalent to @code{@@samp} in its effects. +For example: + +@example +The option @@option@{-l@} produces a long listing. +@end example +@noindent produces +@quotation +The option @option{-l} produces a long listing. +@end quotation + +In tables, putting options inside @code{@@code} produces a +more pleasing effect. + +@node dfn +@comment node-name, next, previous, up +@subsection @code{@@dfn}@{@var{term}@} +@findex dfn + +Use the @code{@@dfn} command to identify the introductory or defining +use of a technical term. Use the command only in passages whose +purpose is to introduce a term which will be used again or which the +reader ought to know. Mere passing mention of a term for the first +time does not deserve @code{@@dfn}. The command generates italics in +the printed manual, and double quotation marks in the Info file. For +example:@refill + +@example +Getting rid of a file is called @@dfn@{deleting@} it. +@end example + +@noindent +produces + +@quotation +Getting rid of a file is called @dfn{deleting} it. +@end quotation + +As a general rule, a sentence containing the defining occurrence of a +term should be a definition of the term. The sentence does not need +to say explicitly that it is a definition, but it should contain the +information of a definition---it should make the meaning clear. + +@ignore +@c node ctrl, , cite, Indicating +@comment node-name, next, previous, up +@c subsection @code{@@ctrl}@{@var{ctrl-char}@} +@findex ctrl + +The @code{@@ctrl} command is seldom used. It describes an ASCII +control character by inserting the actual character into the Info +file. + +Usually, in Texinfo, you talk what you type as keyboard entry by +describing it with @code{@@kbd}: thus, @samp{@@kbd@{C-a@}} for +@kbd{C-a}. Use @code{@@kbd} in this way when talking about a control +character that is typed on the keyboard by the user. When talking +about a control character appearing in a file or a string, do not use +@code{@@kbd} since the control character is not typed. Also, do not +use @samp{C-} but spell out @code{control-}, as in @samp{control-a}, +to make it easier for a reader to understand.@refill + +@code{@@ctrl} is an idea from the beginnings of Texinfo which may not +really fit in to the scheme of things. But there may be times when +you want to use the command. The pattern is +@code{@@ctrl@{@var{ch}@}}, where @var{ch} is an ASCII character +whose control-equivalent is wanted. For example, to specify +@samp{control-f}, you would enter@refill + +@example +@@ctrl@{f@} +@end example + +@noindent +produces + +@quotation +@ctrl{f} +@end quotation + +In the Info file, this generates the specified control character, output +literally into the file. This is done so a user can copy the specified +control character (along with whatever else he or she wants) into another +Emacs buffer and use it. Since the `control-h',`control-i', and +`control-j' characters are formatting characters, they should not be +indicated with @code{@@ctrl}.@refill + +In a printed manual, @code{@@ctrl} generates text to describe or +identify that control character: an uparrow followed by the character +@var{ch}.@refill +@end ignore + + +@node abbr +@subsection @code{@@abbr}@{@var{abbreviation}[, @var{meaning}]@} +@findex abbr + +@cindex Abbreviations, tagging +You can use the @code{@@abbr} command for general abbreviations. The +abbreviation is given as the single argument in braces, as in +@samp{@@abbr@{Comput.@}}. As a matter of style, or for particular +abbreviations, you may prefer to omit periods, as in +@samp{@@abbr@{Mr@} Stallman}. + +@code{@@abbr} accepts an optional second argument, intended to be used +for the meaning of the abbreviation. + +If the abbreviation ends with a lowercase letter and a period, and is +not at the end of a sentence, and has no second argument, remember to +use the @code{@@.} command (@pxref{Not Ending a +Sentence}) to get the correct spacing. However, you do not have to +use @code{@@.} within the abbreviation itself; Texinfo automatically +assumes periods within the abbreviation do not end a sentence. + +@cindex <abbr> and <abbrev> tags +In @TeX{} and in the Info output, the first argument is printed as-is; +if the second argument is present, it is printed in parentheses after +the abbreviation. In HTML and XML, the @code{<abbr>} tag is +used; in Docbook, the @code{<abbrev>} tag is used. For instance: + +@example +@@abbr@{Comput. J., Computer Journal@} +@end example + +@noindent produces: + +@display +@abbr{Comput. J., Computer Journal} +@end display + +For abbreviations consisting of all capital letters, you may prefer to +use the @code{@@acronym} command instead. See the next section for +more on the usage of these two commands. + + +@node acronym +@subsection @code{@@acronym}@{@var{acronym}[, @var{meaning}]@} +@findex acronym + +@cindex NASA, as acronym +@cindex Acronyms, tagging +Use the @code{@@acronym} command for abbreviations written in all +capital letters, such as `@acronym{NASA}'. The abbreviation is given as +the single argument in braces, as in @samp{@@acronym@{NASA@}}. As +a matter of style, or for particular acronyms, you may prefer to +use periods, as in @samp{@@acronym@{N.A.S.A.@}}. + +@code{@@acronym} accepts an optional second argument, intended to be +used for the meaning of the acronym. + +If the acronym is at the end of a sentence, and if there is no second +argument, remember to use the @code{@@.} or similar command +(@pxref{Ending a Sentence}) to get the correct spacing. + +@cindex <acronym> tag +In @TeX{}, the acronym is printed in slightly smaller font. In the +Info output, the argument is printed as-is. In either format, if the +second argument is present, it is printed in parentheses after the +acronym. In HTML, Docbook, and XML, the @code{<acronym>} tag is +used. + +For instance (since GNU is a recursive acronym, we use +@code{@@acronym} recursively): + +@example +@@acronym@{GNU, @@acronym@{GNU@}'s Not Unix@} +@end example + +@noindent produces: + +@display +@acronym{GNU, @acronym{GNU}'s Not Unix} +@end display + +@cindex Family names, in all capitals +In some circumstances, it is conventional to print family names in all +capitals. Don't use @code{@@acronym} for this, since a name is not an +acronym. Use @code{@@sc} instead (@pxref{Smallcaps}). + +@code{@@abbr} and @code{@@acronym} are closely related commands: they +both signal to the reader that a shortened form is being used, and +possibly give a meaning. When choosing whether to use these two +commands, please bear the following in mind. + +@itemize @minus +@item +In standard English usage, acronyms are a subset of abbreviations: +they include pronounceable words like `@acronym{NATO}', `radar', and +`snafu', and some sources also include syllable acronyms like +`Usenet', hybrids like `@acronym{SIGGRAPH}', and unpronounceable +initialisms like `@acronym{FBI}'. + +@item +In Texinfo, an acronym (but not an abbreviation) should consist only +of capital letters and periods, no lowercase. + +@item +In @TeX{}, an acronym (but not an abbreviation) is printed in a +slightly smaller font. + +@item +Some browsers place a dotted bottom border under abbreviations but not +acronyms. + +@item +It's not essential to use either of these commands for all +abbreviations; use your judgment. Text is perfectly readable without +them. + +@end itemize + + +@node indicateurl +@subsection @code{@@indicateurl}@{@var{uniform-resource-locator}@} +@findex indicateurl +@cindex Uniform resource locator, indicating +@cindex URL, indicating + +Use the @code{@@indicateurl} command to indicate a uniform resource +locator on the World Wide Web. This is analogous to @code{@@file}, +@code{@@var}, etc., and is purely for markup purposes. It does not +produce a link you can follow in HTML output (use the @code{@@uref} +command for that, @pxref{uref,, @code{@@uref}}). It is useful for +url's which do not actually exist. For example: + +@example +For example, the url might be @@indicateurl@{http://example.org/path@}. +@end example + +@noindent which produces: + +@display +For example, the url might be @indicateurl{http://example.org/path}. +@end display + + +@node email +@subsection @code{@@email}@{@var{email-address}[, @var{displayed-text}]@} +@findex email + +Use the @code{@@email} command to indicate an electronic mail address. +It takes one mandatory argument, the address, and one optional argument, the +text to display (the default is the address itself). + +@cindex Mailto link +In Info, the address is shown in angle brackets, preceded by the text +to display if any. In @TeX{}, the angle brackets are omitted. In +HTML output, @code{@@email} produces a @samp{mailto} link that usually +brings up a mail composition window. For example: + +@example +Send bug reports to @@email@{bug-texinfo@@@@gnu.org@}, +suggestions to the @@email@{bug-texinfo@@@@gnu.org, same place@}. +@end example +@noindent produces +@display +Send bug reports to @email{bug-texinfo@@gnu.org}, +suggestions to the @email{bug-texinfo@@gnu.org, same place}. +@end display + + +@node Emphasis +@section Emphasizing Text +@cindex Emphasizing text + +Usually, Texinfo changes the font to mark words in the text according to +what category the words belong to; an example is the @code{@@code} command. +Most often, this is the best way to mark words. +However, sometimes you will want to emphasize text without indicating a +category. Texinfo has two commands to do this. Also, Texinfo has +several commands that specify the font in which @TeX{} will typeset +text. These commands have no effect on Info and only one of them, +the @code{@@r} command, has any regular use.@refill + +@menu +* emph & strong:: How to emphasize text in Texinfo. +* Smallcaps:: How to use the small caps font. +* Fonts:: Various font commands for printed output. +@end menu + +@node emph & strong +@subsection @code{@@emph}@{@var{text}@} and @code{@@strong}@{@var{text}@} +@cindex Emphasizing text, font for +@findex emph +@findex strong + +The @code{@@emph} and @code{@@strong} commands are for emphasis; +@code{@@strong} is stronger. In printed output, @code{@@emph} produces +@emph{italics} and @code{@@strong} produces @strong{bold}. + +For example, + +@example +@group +@@strong@{Caution:@} @@samp@{rm * .[^.]*@} +removes @@emph@{all@} files in the directory. +@end group +@end example + +@noindent +produces the following in printed output and HTML: + +@quotation +@strong{Caution}: @samp{rm * .[^.]*} +removes @emph{all} files in the directory. +@end quotation + +@noindent +and the following in Info: + +@example +*Caution:* `rm * .[^.]*' removes _all_ +files in the directory. +@end example + +The @code{@@strong} command is seldom used except to mark what is, in +effect, a typographical element, such as the word `Caution' in the +preceding example. + +In the Info output, @code{@@emph} surrounds the text with underscores +(@samp{_}), and @code{@@strong} puts asterisks around the text. + +@quotation Caution +Do not use @code{@@strong} with the word @samp{Note}; Info will +mistake the combination for a cross reference. (It's usually +redundant, anyway.) Use a phrase such as @strong{Please notice} or +@strong{Caution} instead, or the optional argument to +@code{@@quotation}---@samp{Note} is allowable there. +@end quotation + + +@node Smallcaps +@subsection @code{@@sc}@{@var{text}@}: The Small Caps Font +@cindex Small caps font +@findex sc @r{(small caps font)} + +Use the @samp{@@sc} command to set text in @sc{a small caps font} +(where possible). Write the text you want to be in small caps between +braces in lower case, like this: + +@example +Richard @@sc@{Stallman@} founded @@acronym@{GNU@}. +@end example + +@noindent +This produces: + +@display +Richard @sc{Stallman} founded @acronym{GNU}. +@end display + +As shown here, we recommend using @code{@@acronym} for actual +acronyms (@pxref{acronym}), and reserving @code{@@sc} for special +cases where you want small caps. The output is not the same +(@code{@@acronym} prints in a smaller text font, not the small caps +font), but more importantly it describes the actual text more +accurately. + +Family names are one case where small capitals are sometimes desirable, +also as shown here. + +@cindex <small> tag +@TeX{} typesets any uppercase letters between the braces of an +@code{@@sc} command in full-size capitals; only lowercase letters are +printed in the small caps font. In the Info output, the argument to +@code{@@sc} is printed in all upper case. In HTML, the argument is +uppercased and the output marked with the @code{<small>} tag to reduce +the font size. + +Since it's redundant to mark all-uppercase text with @code{@@sc}, +@command{makeinfo} warns about such usage. + +We recommend using regular mixed case wherever possible. + + +@node Fonts +@subsection Fonts for Printing, Not Info +@cindex Fonts for printing, not Info + +@findex fonttextsize +@cindex Font size, reducing +@cindex Reducing font size +@cindex Smaller fonts +Texinfo provides one command to change the size of the main body font +in the @TeX{} output for a document: @code{@@fonttextsize}. It has no +effect at all in other output. It takes a single argument on the +remainder of the line, which must be either @samp{10} or @samp{11}. +For example: + +@example +@@fonttextsize 10 +@end example + +@cindex Printing cost, reducing +The effect is to reduce the body font to a 10@dmn{pt} size (the +default is 11@dmn{pt}). Fonts for other elements, such as sections +and chapters, are reduced accordingly. This should only be used in +conjunction with @code{@@smallbook} (@pxref{smallbook,,Printing +``Small'' Books}) or similar, since 10@dmn{pt} fonts on standard paper +(8.5x11 or A4) are too small. One reason to use this command is to +save pages, and hence printing cost, for physical books. + +Texinfo does not at present have commands to switch the font family +to use, or more general size-changing commands. + +@cindex Styles, font +Texinfo also provides a number of font commands that specify font changes +in the printed manual and (where possible) in the HTML output, but +have no effect in the Info file. All the commands apply to an +argument that follows, surrounded by braces. + +@table @code +@item @@b +@findex b @r{(bold font)} +@cindex Bold font +selects @b{bold} face; + +@item @@i +@findex i @r{(italic font)} +@cindex Italic font +selects an @i{italic} font; + +@item @@r +@findex r @r{(roman font)} +@cindex Roman font +@cindex Default font +selects a @r{roman} font, which is the usual font in which text is +printed. It may or may not be seriffed. + +@item @@sansserif +@findex sansserif @r{(sans serif font)} +@cindex Sans serif font +selects a @sansserif{sans serif} font; + +@item @@slanted +@findex slanted @r{(slanted font)} +@cindex Slanted font +@cindex Oblique font +selects a @slanted{slanted} font; + +@item @@t +@findex t @r{(typewriter font)} +@cindex Monospace font +@cindex Fixed-width font +@cindex Typewriter font +selects the @t{fixed-width}, typewriter-style font used by @code{@@code}; + +@end table + +(The commands with longer names were invented much later than the +others, at which time it did not seem desirable to use very short +names for such an infrequently needed feature.) + +@cindex <lineannotation> Docbook tag +Only the @code{@@r} command has much use: in example-like +environments, you can use the @code{@@r} command to write comments in +the standard roman font instead of the fixed-width font. This looks +better in printed output, and produces a @code{<lineannotation>} tag +in Docbook output. + +For example, + +@example +@group +@@lisp +(+ 2 2) ; @@r@{Add two plus two.@} +@@end lisp +@end group +@end example + +@noindent +produces + +@lisp +(+ 2 2) ; @r{Add two plus two.} +@end lisp + +In general, you should avoid using the other font commands. Some of +them are only useful when documenting functionality of specific font +effects, such as in @TeX{} and related packages. + + +@node Quotations and Examples +@chapter Quotations and Examples + +Quotations and examples are blocks of text consisting of one or more +whole paragraphs that are set off from the bulk of the text and +treated differently. They are usually indented in the output. + +@findex end +In Texinfo, you always begin a quotation or example by writing an +@@-command at the beginning of a line by itself, and end it by writing +an @code{@@end} command that is also at the beginning of a line by +itself. For instance, you begin an example by writing @code{@@example} +by itself at the beginning of a line and end the example by writing +@code{@@end example} on a line by itself, at the beginning of that +line, and with only one space between the @code{@@end} and the +@code{example}. + +@menu +* Block Enclosing Commands:: Different constructs for different purposes. +* quotation:: Writing a quotation. +* example:: Writing an example in a fixed-width font. +* verbatim:: Writing a verbatim example. +* verbatiminclude:: Including a file verbatim. +* lisp:: Illustrating Lisp code. +* small:: Examples in a smaller font. +* display:: Writing an example in the current font. +* format:: Writing an example without narrowed margins. +* exdent:: Undo indentation on a line. +* flushleft & flushright:: Pushing text flush left or flush right. +* noindent:: Preventing paragraph indentation. +* indent:: Forcing paragraph indentation. +* cartouche:: Drawing rounded rectangles around examples. +@end menu + + +@node Block Enclosing Commands +@section Block Enclosing Commands + +Here are commands for quotations and examples, explained further in the +following sections: + +@table @code +@item @@quotation +Indicate text that is quoted. The text is filled, indented (from both +margins), and printed in a roman font by default. + +@item @@example +Illustrate code, commands, and the like. The text is printed +in a fixed-width font, and indented but not filled. + +@item @@verbatim +Mark a piece of text that is to be printed verbatim; no character +substitutions are made and all commands are ignored, until the next +@code{@@end verbatim}. The text is printed in a fixed-width font, +and not indented or filled. Extra spaces and blank lines are +significant, and tabs are expanded. + +@item @@smallexample +Same as @code{@@example}, except that in @TeX{} this command typesets +text in a smaller font. + +@item @@lisp +Like @code{@@example}, but specifically for illustrating Lisp code. The +text is printed in a fixed-width font, and indented but not filled. + +@item @@smalllisp +Is to @code{@@lisp} as @code{@@smallexample} is to @code{@@example}. + +@item @@display +Display illustrative text. The text is indented but not filled, and +no font is selected (so, by default, the font is roman).@refill + +@item @@smalldisplay +Is to @code{@@display} as @code{@@smallexample} is to @code{@@example}. + +@item @@format +Like @code{@@display} (the text is not filled and no font is selected), +but the text is not indented. + +@item @@smallformat +Is to @code{@@format} as @code{@@smallexample} is to @code{@@example}. +@end table + +The @code{@@exdent} command is used within the above constructs to +undo the indentation of a line. + +The @code{@@flushleft} and @code{@@flushright} commands are used to line +up the left or right margins of unfilled text.@refill + +The @code{@@noindent} command may be used after one of the above +constructs to prevent the following text from being indented as a new +paragraph. + +You can use the @code{@@cartouche} environment around one of the above +constructs to highlight the example or quotation by drawing a box with +rounded corners around it. @xref{cartouche, , Drawing Cartouches Around +Examples}. + + +@node quotation +@section @code{@@quotation}: Block quotations +@cindex Quotations +@findex quotation + +The text of a quotation is processed normally (regular font, text is +filled) except that: + +@itemize @bullet +@item +the margins are closer to the center of the page, so the whole of the +quotation is indented; + +@item +and the first lines of paragraphs are indented no more than other lines. + +@end itemize + +@quotation +This is an example of text written between an @code{@@quotation} +command and an @code{@@end quotation} command. An @code{@@quotation} +command is most often used to indicate text that is excerpted from +another (real or hypothetical) printed work. +@end quotation + +Write an @code{@@quotation} command as text on a line by itself. This +line will disappear from the output. Mark the end of the quotation +with a line beginning with and containing only @code{@@end quotation}. +The @code{@@end quotation} line will likewise disappear from the +output. + +@code{@@quotation} takes one optional argument, given on the remainder +of the line. This text, if present, is included at the beginning of +the quotation in bold or otherwise emphasized, and followed with a +@samp{:}. For example: + +@example +@@quotation Note +This is +a foo. +@@end quotation +@end example + +@noindent +produces + +@quotation Note +This is +a foo. +@end quotation + +If the @code{@@quotation} argument is exactly one of these words: + +@example +Caution Important Note Tip Warning +@end example + +@cindex <note> Docbook tag +@cindex <blockquote> HTML tag +@noindent then the Docbook output uses corresponding special tags +(@code{<note>}, etc.) instead of the default @code{<blockquote>}. +HTML output always uses @code{<blockquote>}. + + +@node example +@section @code{@@example}: Example Text +@cindex Examples, formatting them +@cindex Formatting examples +@findex example + +The @code{@@example} environment is used to indicate an example that +is not part of the running text, such as computer input or output. +Write an @code{@@example} command at the beginning of a line by +itself. Mark the end of the example with an @code{@@end example} +command, also written at the beginning of a line by itself. + +An @code{@@example} environment has the following characteristics: + +@itemize +@item Each line in the input file is a line in the output; that is, +the source text is not filled as it normally is. +@item Extra spaces and blank lines are significant. +@item The output is indented. +@item The output uses a fixed-width font. +@item Texinfo commands @emph{are} expanded; if you want the output to +be the input verbatim, use the @code{@@verbatim} environment instead +(@pxref{verbatim,,@code{@@verbatim}}). +@end itemize + +For example, + +@example +@@example +cp foo @@var@{dest1@}; \ + cp foo @@var@{dest2@} +@@end example +@end example + +@noindent +produces + +@example +cp foo @var{dest1}; \ + cp foo @var{dest2} +@end example + +The lines containing @code{@@example} and @code{@@end example} will +disappear from the output. To make the output look good, you should +put a blank line before the @code{@@example} and another blank line +after the @code{@@end example}. Blank lines inside the beginning +@code{@@example} and the ending @code{@@end example}, on the other +hand, do appear in the output. + +@quotation Caution +Do not use tabs in the lines of an example! (Or anywhere else in +Texinfo, except in verbatim environments.) @TeX{} treats tabs as +single spaces, and that is not what they look like. In Emacs, you can +use @kbd{M-x untabify} to convert tabs in a region to multiple spaces. +@end quotation + +Examples are often, logically speaking, ``in the middle'' of a +paragraph, and the text that continues afterwards should not be +indented, as in the example above. The @code{@@noindent} command +prevents a piece of text from being indented as if it were a new +paragraph (@pxref{noindent,,@code{@@noindent}}. + +If you want to embed code fragments within sentences, instead of +displaying them, use the @code{@@code} command or its relatives +(@pxref{code,,@code{@@code}}). + +If you wish to write a ``comment'' on a line of an example in the +normal roman font, you can use the @code{@@r} command (@pxref{Fonts}). + + +@node verbatim +@section @code{@@verbatim}: Literal Text +@findex verbatim +@cindex Verbatim environment + +Use the @code{@@verbatim} environment for printing of text that may +contain special characters or commands that should not be interpreted, +such as computer input or output (@code{@@example} interprets its text +as regular Texinfo commands). This is especially useful for including automatically +generated files in a Texinfo manual. + +In general, the output will be just the same as the input. No +character substitutions are made, e.g., all spaces and blank lines are +significant, including tabs. In the printed manual, the text is +typeset in a fixed-width font, and not indented or filled. + +Write a @code{@@verbatim} command at the beginning of a line by itself. +This line will disappear from the output. Mark the end of the verbatim +block with a @code{@@end verbatim} command, also written at the +beginning of a line by itself. The @code{@@end verbatim} will also +disappear from the output. + +For example: +@c oops, got to trick this a bit: can't use @end verbatim inside @verbatim + +@example +@exdent @t{@@verbatim} +@exdent @t{@{} +@exdent @key{TAB}@t{@@command with strange characters: @@'e} +@exdent @t{expand@key{TAB}me} +@exdent @t{@}} +@exdent @t{@@end verbatim} +@end example + +@noindent +This produces: + +@verbatim +{ + @command with strange characters: @'e +expand me +} +@end verbatim + +Since the lines containing @code{@@verbatim} and @code{@@end verbatim} +produce no output, typically you should put a blank line before the +@code{@@verbatim} and another blank line after the @code{@@end +verbatim}. Blank lines between the beginning @code{@@verbatim} and +the ending @code{@@end verbatim} will appear in the output. + +@cindex Verbatim, small +@cindex Small verbatim +You can get a ``small'' verbatim by enclosing the @code{@@verbatim} in +an @code{@@smallformat} environment, as shown here: + +@c more cheating ... +@smallexample +@exdent @t{@@smallformat} +@exdent @t{@@verbatim} +@exdent @t{... still verbatim, but in a smaller font ...} +@exdent @t{@@end verbatim} +@exdent @t{@@end smallformat} +@end smallexample + +Finally, a word of warning: it is not reliable to use +@code{@@verbatim} inside other Texinfo constructs. + + +@node verbatiminclude +@section @code{@@verbatiminclude} @var{file}: Include a File Verbatim +@cindex Verbatim, include file +@cindex Including a file verbatim +@findex verbatiminclude + +You can include the exact contents of a file in the document with the +@code{@@verbatiminclude} command: + +@example +@@verbatiminclude @var{filename} +@end example + +The contents of @var{filename} is printed in a verbatim environment +(@pxref{verbatim,,@code{@@verbatim}}). Generally, the file is printed +exactly as it is, with all special characters and white space +retained. No indentation is added; if you want indentation, enclose +the @code{@@verbatiminclude} within @code{@@example} +(@pxref{example,,@code{@@example}}). + +The name of the file is taken literally, with a single exception: +@code{@@value@{@var{var}@}} references are expanded. This makes it +possible to include files in other directories within a distribution, +for instance: + +@example +@@verbatiminclude @@value@{top_srcdir@}/NEWS +@end example + +@noindent (You still have to get @code{top_srcdir} defined in the +first place.) + +For a method on printing the file contents in a smaller font size, see +the end of the previous section on @code{@@verbatim}. + + +@node lisp +@section @code{@@lisp}: Marking a Lisp Example +@findex lisp +@cindex Lisp example + +The @code{@@lisp} command is used for Lisp code. It is synonymous +with the @code{@@example} command. + +@lisp +This is an example of text written between an +@code{@@lisp} command and an @code{@@end lisp} command. +@end lisp + +Use @code{@@lisp} instead of @code{@@example} to preserve information +regarding the nature of the example. This is useful, for example, if +you write a function that evaluates only and all the Lisp code in a +Texinfo file. Then you can use the Texinfo file as a Lisp +library.@footnote{It would be straightforward to extend Texinfo to work +in a similar fashion for C, Fortran, or other languages.} + +Mark the end of @code{@@lisp} with @code{@@end lisp} on a line by +itself. + + +@node small +@section @code{@@small@dots{}} Block Commands +@cindex Small examples +@cindex Examples in smaller fonts +@cindex Lisp examples in smaller fonts +@findex smalldisplay +@findex smallexample +@findex smallformat +@findex smalllisp + +In addition to the regular @code{@@example} and @code{@@lisp} commands, +Texinfo has ``small'' example-style commands. These are +@code{@@smalldisplay}, @code{@@smallexample}, @code{@@smallformat}, and +@code{@@smalllisp}. + +In Info, the @code{@@small@dots{}} commands are equivalent to their +non-small companion commands. + +In @TeX{}, however, the @code{@@small@dots{}} commands typeset text in +a smaller font than the non-small example commands. Consequently, +many examples containing long lines fit on a page without needing to +be shortened. + +Mark the end of an @code{@@small@dots{}} block with a corresponding +@code{@@end small@dots{}}. For example, pair @code{@@smallexample} with +@code{@@end smallexample}. + +Here is an example of the font used by the @code{@@small@dots{}} +commands (in Info, the output will be the same as usual): + +@smallexample +@dots{} to make sure that you have the freedom to +distribute copies of free software (and charge for +this service if you wish), that you receive source +code or can get it if you want it, that you can +change the software or use pieces of it in new free +programs; and that you know you can do these things. +@end smallexample + +The @code{@@small@dots{}} commands make it easier to prepare manuals +without forcing you to edit examples by hand to fit them onto narrower +pages. + +As a general rule, a printed document looks much better if you use +only one of (for instance) @code{@@example} or @code{@@smallexample} +consistently within a chapter. + + +@node display +@section @code{@@display} and @code{@@smalldisplay} +@cindex Display formatting +@findex display + +The @code{@@display} command begins a kind of example, where each line +of input produces a line of output, and the output is indented. It is +thus like the @code{@@example} command except that, in a printed +manual, @code{@@display} does not select the fixed-width font. In +fact, it does not specify the font at all, so that the text appears in +the same font it would have appeared in without the @code{@@display} +command. + +@display +This is an example of text written between an @code{@@display} command +and an @code{@@end display} command. The @code{@@display} command +indents the text, but does not fill it. +@end display + +@findex smalldisplay +Texinfo also provides a command @code{@@smalldisplay}, which is like +@code{@@display} but uses a smaller font in @code{@@smallbook} format. +@xref{small}. + +The @code{@@table} command (@pxref{table}) does not work inside +@code{@@display}. Since @code{@@display} is line-oriented, it doesn't +make sense to use them together. If you want to indent a table, try +@code{@@quotation} (@pxref{quotation}). + + +@node format +@section @code{@@format} and @code{@@smallformat} +@findex format + +The @code{@@format} command is similar to @code{@@example} except +that, in the printed manual, @code{@@format} does not select the +fixed-width font and does not narrow the margins. + +@format +This is an example of text written between an @code{@@format} command +and an @code{@@end format} command. As you can see +from this example, +the @code{@@format} command does not fill the text. +@end format + +@findex smallformat +Texinfo also provides a command @code{@@smallformat}, which is like +@code{@@format} but uses a smaller font in @code{@@smallbook} format. +@xref{small}. + + + +@node exdent +@section @code{@@exdent}: Undoing a Line's Indentation +@cindex Indentation undoing +@findex exdent + +The @code{@@exdent} command removes any indentation a line might have. +The command is written at the beginning of a line and applies only to +the text that follows the command that is on the same line. Do not use +braces around the text. In a printed manual, the text on an +@code{@@exdent} line is printed in the roman font.@refill + +@code{@@exdent} is usually used within examples. Thus,@refill + +@example +@group +@@example +This line follows an @@@@example command. +@@exdent This line is exdented. +This line follows the exdented line. +The @@@@end example comes on the next line. +@@end example +@end group +@end example + +@noindent +produces + +@example +@group +This line follows an @@example command. +@exdent This line is exdented. +This line follows the exdented line. +The @@end example comes on the next line. +@end group +@end example + +In practice, the @code{@@exdent} command is rarely used. +Usually, you un-indent text by ending the example and +returning the page to its normal width.@refill + + +@node flushleft & flushright +@section @code{@@flushleft} and @code{@@flushright} +@findex flushleft +@findex flushright +@cindex Ragged right +@cindex Ragged left + +The @code{@@flushleft} and @code{@@flushright} commands line up the +ends of lines on the left and right margins of a page, +but do not fill the text. The commands are written on lines of their +own, without braces. The @code{@@flushleft} and @code{@@flushright} +commands are ended by @code{@@end flushleft} and @code{@@end +flushright} commands on lines of their own.@refill + +@need 1500 +For example, + +@example +@group +@@flushleft +This text is +written flushleft. +@@end flushleft +@end group +@end example + +@noindent +produces + +@quotation +@flushleft +This text is +written flushleft. +@end flushleft +@end quotation + + +@code{@@flushright} produces the type of indentation often used in the +return address of letters. For example, + +@example +@group +@@flushright +Here is an example of text written +flushright. The @@code@{@@flushright@} command +right justifies every line but leaves the +left end ragged. +@@end flushright +@end group +@end example + +@noindent +produces + +@flushright +Here is an example of text written +flushright. The @code{@@flushright} command +right justifies every line but leaves the +left end ragged. +@end flushright + + +@node noindent +@section @code{@@noindent}: Omitting Indentation +@cindex Omitting indentation +@cindex Suppressing indentation +@cindex Indentation, omitting +@findex noindent + +An example or other inclusion can break a paragraph into segments. +Ordinarily, the formatters indent text that follows an example as a new +paragraph. You can prevent this on a case-by-case basis by writing +@code{@@noindent} at the beginning of a line, preceding the continuation +text. You can also disable indentation for all paragraphs globally with +@code{@@paragraphindent} (@pxref{paragraphindent, Paragraph Indenting}). + +It is best to write @code{@@noindent} on a line by itself, since in most +environments, spaces following the command will not be ignored. It's ok +to use it at the beginning of a line, with text following, outside of +any environment. + +@need 1500 +For example: + +@example +@group +@@example +This is an example +@@end example + +@@noindent +This line is not indented. As you can see, the +beginning of the line is fully flush left with the line +that follows after it. (This whole example is between +@@code@{@@@@display@} and @@code@{@@@@end display@}.) +@end group +@end example + +@noindent produces: + +@display + +@example +This is an example +@end example + +@noindent +This line is not indented. As you can see, the +beginning of the line is fully flush left with the line +that follows after it. (This whole example is between +@code{@@display} and @code{@@end display}.) + +@end display + +To adjust the number of blank lines properly in the Info file output, +remember that the line containing @code{@@noindent} does not generate a +blank line, and neither does the @code{@@end example} line. + +In the Texinfo source file for this manual, each line that says +`produces' is preceded by @code{@@noindent}. + +Do not put braces after an @code{@@noindent} command; they are not +necessary, since @code{@@noindent} is a command used outside of +paragraphs (@pxref{Command Syntax}). + + +@node indent +@section @code{@@indent}: Forcing Indentation +@cindex Forcing indentation +@cindex Inserting indentation +@cindex Indentation, forcing +@findex indent + +@indent +To complement the @code{@@noindent} command (see the previous +section), Texinfo provides the @code{@@indent} command that forces a +paragraph to be indented. This paragraph, for instance, is indented +using an @code{@@indent} command. The first paragraph of a section is +the most likely place to use @code{@@indent}, to override the normal +behavior of no indentation there (@pxref{paragraphindent}). + +It is best to write @code{@@indent} on a line by itself, since in most +environments, spaces following the command will not be ignored. The +@code{@@indent} line will not generate a blank line in the Info output +within an environment. + +However, it is ok to use it at the beginning of a line, with text +following, outside of any environment. + +Do not put braces after an @code{@@indent} command; they are not +necessary, since @code{@@indent} is a command used outside of +paragraphs (@pxref{Command Syntax}). + + +@node cartouche +@section @code{@@cartouche}: Rounded Rectangles Around Examples +@findex cartouche +@cindex Box with rounded corners +@cindex Rounded rectangles, around examples + +In a printed manual, the @code{@@cartouche} command draws a box with +rounded corners around its contents. In HTML, a normal rectangle is +drawn (that's the best HTML can do). @code{@@cartouche} has no effect +in Info output. + +You can use this command to further highlight an example or quotation. +For instance, you could write a manual in which one type of example is +surrounded by a cartouche for emphasis. + +For example, + +@example +@@cartouche +@@example +% pwd +/usr/local/share/emacs +@@end example +@@end cartouche +@end example + +@noindent +surrounds the two-line example with a box with rounded corners, in the +printed manual. + +The output from the example looks like this (if you're reading this in +Info, you'll see the @code{@@cartouche} had no effect): + +@cartouche +@example +% pwd +/usr/local/info +@end example +@end cartouche + +For proper output in HTML, it's necessary to put the +@code{@@cartouche} around the @code{@@example}, and not the other way +around. This limitation of @command{makeinfo} may be removed one day. + +@code{@@cartouche} also implies @code{@@group} (@pxref{group}). + +@node Lists and Tables +@chapter Lists and Tables +@cindex Making lists and tables +@cindex Lists and tables, making +@cindex Tables and lists, making + +Texinfo has several ways of making lists and tables. Lists can be +bulleted or numbered; two-column tables can highlight the items in +the first column; multi-column tables are also supported. + +@menu +* Introducing Lists:: Texinfo formats lists for you. +* itemize:: How to construct a simple list. +* enumerate:: How to construct a numbered list. +* Two-column Tables:: How to construct a two-column table. +* Multi-column Tables:: How to construct generalized tables. +@end menu + +@node Introducing Lists +@section Introducing Lists + +Texinfo automatically indents the text in lists or tables, and numbers +an enumerated list. This last feature is useful if you modify the +list, since you do not need to renumber it yourself.@refill + +Numbered lists and tables begin with the appropriate @@-command at the +beginning of a line, and end with the corresponding @code{@@end} +command on a line by itself. The table and itemized-list commands +also require that you write formatting information on the same line as +the beginning @@-command.@refill + +Begin an enumerated list, for example, with an @code{@@enumerate} +command and end the list with an @code{@@end enumerate} command. +Begin an itemized list with an @code{@@itemize} command, followed on +the same line by a formatting command such as @code{@@bullet}, and end +the list with an @code{@@end itemize} command.@refill +@findex end + +Precede each element of a list with an @code{@@item} or @code{@@itemx} +command.@refill + +@sp 1 +@noindent +Here is an itemized list of the different kinds of table and lists:@refill + +@itemize @bullet +@item +Itemized lists with and without bullets. + +@item +Enumerated lists, using numbers or letters. + +@item +Two-column tables with highlighting. +@end itemize + +@sp 1 +@noindent +Here is an enumerated list with the same items:@refill + +@enumerate +@item +Itemized lists with and without bullets. + +@item +Enumerated lists, using numbers or letters. + +@item +Two-column tables with highlighting. +@end enumerate + +@sp 1 +@noindent +And here is a two-column table with the same items and their +@w{@@-commands}:@refill + +@table @code +@item @@itemize +Itemized lists with and without bullets. + +@item @@enumerate +Enumerated lists, using numbers or letters. + +@item @@table +@itemx @@ftable +@itemx @@vtable +Two-column tables, optionally with indexing. +@end table + + +@node itemize +@section @code{@@itemize}: Making an Itemized List +@cindex Itemization +@findex itemize + +The @code{@@itemize} command produces sequences of indented +paragraphs, with a bullet or other mark inside the left margin +at the beginning of each paragraph for which such a mark is desired.@refill + +@cindex @code{@@w}, for blank items +Begin an itemized list by writing @code{@@itemize} at the beginning of +a line. Follow the command, on the same line, with a character or a +Texinfo command that generates a mark. Usually, you will write +@code{@@bullet} after @code{@@itemize}, but you can use +@code{@@minus}, or any command or character that results in a single +character in the Info file. If you don't want any mark at all, use +@code{@@w}. (When you write the mark command such as +@code{@@bullet} after an @code{@@itemize} command, you may omit the +@samp{@{@}}.) If you don't specify a mark command, the default is +@code{@@bullet}. + +Write the text of the indented paragraphs themselves after the +@code{@@itemize}, up to another line that says @code{@@end +itemize}.@refill + +@findex item +At the beginning of each paragraph for which a mark in the margin is +desired, write a line that starts with @code{@@item}. It is ok to +have text following the @code{@@item}. + +Usually, you should put a blank line before an @code{@@item}. This +puts a blank line in the Info file. (@TeX{} inserts the proper +interline whitespace in either case.) Except when the entries are +very brief, these blank lines make the list look better.@refill + +Here is an example of the use of @code{@@itemize}, followed by the +output it produces. @code{@@bullet} produces an @samp{*} in Info and a +round dot in @TeX{}. + +@example +@group +@@itemize @@bullet +@@item +Some text for foo. + +@@item +Some text +for bar. +@@end itemize +@end group +@end example + +@noindent +This produces: + +@quotation +@itemize @bullet +@item +Some text for foo. + +@item +Some text +for bar. +@end itemize +@end quotation + +Itemized lists may be embedded within other itemized lists. Here is a +list marked with dashes embedded in a list marked with bullets:@refill + +@example +@group +@@itemize @@bullet +@@item +First item. + +@@itemize @@minus +@@item +Inner item. + +@@item +Second inner item. +@@end itemize + +@@item +Second outer item. +@@end itemize +@end group +@end example + +@noindent +This produces: + +@quotation +@itemize @bullet +@item +First item. + +@itemize @minus +@item +Inner item. + +@item +Second inner item. +@end itemize + +@item +Second outer item. +@end itemize +@end quotation + + +@node enumerate +@section @code{@@enumerate}: Making a Numbered or Lettered List +@cindex Enumeration +@findex enumerate + +@code{@@enumerate} is like @code{@@itemize} (@pxref{itemize,, +@code{@@itemize}}), except that the labels on the items are +successive integers or letters instead of bullets. + +Write the @code{@@enumerate} command at the beginning of a line. The +command does not require an argument, but accepts either a number or a +letter as an option. Without an argument, @code{@@enumerate} starts the +list with the number @samp{1}. With a numeric argument, such as +@samp{3}, the command starts the list with that number. With an upper +or lower case letter, such as @samp{a} or @samp{A}, the command starts +the list with that letter. + +Write the text of the enumerated list in the same way as an itemized +list: write a line starting with @code{@@item} at the beginning of +each paragraph that you want enumerated. It is ok to have text +following the @code{@@item}. + +You should put a blank line between entries in the list. +This generally makes it easier to read the Info file. + +@need 1500 +Here is an example of @code{@@enumerate} without an argument: + +@example +@group +@@enumerate +@@item +Underlying causes. + +@@item +Proximate causes. +@@end enumerate +@end group +@end example + +@noindent +This produces: + +@enumerate +@item +Underlying causes. + +@item +Proximate causes. +@end enumerate +@sp 1 +Here is an example with an argument of @kbd{3}:@refill +@sp 1 +@example +@group +@@enumerate 3 +@@item +Predisposing causes. + +@@item +Precipitating causes. + +@@item +Perpetuating causes. +@@end enumerate +@end group +@end example + +@noindent +This produces: + +@enumerate 3 +@item +Predisposing causes. + +@item +Precipitating causes. + +@item +Perpetuating causes. +@end enumerate +@sp 1 +Here is a brief summary of the alternatives. The summary is constructed +using @code{@@enumerate} with an argument of @kbd{a}.@refill +@sp 1 +@enumerate a +@item +@code{@@enumerate} + +Without an argument, produce a numbered list, starting with the number +1.@refill + +@item +@code{@@enumerate @var{positive-integer}} + +With a (positive) numeric argument, start a numbered list with that +number. You can use this to continue a list that you interrupted with +other text.@refill + +@item +@code{@@enumerate @var{upper-case-letter}} + +With an upper case letter as argument, start a list +in which each item is marked +by a letter, beginning with that upper case letter.@refill + +@item +@code{@@enumerate @var{lower-case-letter}} + +With a lower case letter as argument, start a list +in which each item is marked by +a letter, beginning with that lower case letter.@refill +@end enumerate + +You can also nest enumerated lists, as in an outline.@refill + +@node Two-column Tables +@section Making a Two-column Table +@cindex Tables, making two-column +@findex table + +@code{@@table} is similar to @code{@@itemize} (@pxref{itemize,, +@code{@@itemize}}), but allows you to specify a name or heading line for +each item. The @code{@@table} command is used to produce two-column +tables, and is especially useful for glossaries, explanatory +exhibits, and command-line option summaries. + +@menu +* table:: How to construct a two-column table. +* ftable vtable:: Automatic indexing for two-column tables. +* itemx:: How to put more entries in the first column. +@end menu + +@node table +@subsection Using the @code{@@table} Command + +@cindex Definition lists, typesetting +Use the @code{@@table} command to produce two-column tables. It is +usually listed for ``definition lists'' of various sorts, where you +have a list of terms and a brief text with each one. + +Write the @code{@@table} command at the beginning of a line, after a +blank line, and follow it on the same line with an argument that is a +Texinfo ``indicating'' command such as @code{@@code}, @code{@@samp}, +@code{@@var}, @code{@@option}, or @code{@@kbd} (@pxref{Indicating}). + +This command will be applied to the text that goes into the first +column of each item and thus determines how it will be highlighted. +For example, @code{@@table @@code} will cause the text in the first +column to be output as if it @code{@@code} command. + +@findex asis +You may also use the @code{@@asis} command as an argument to +@code{@@table}. @code{@@asis} is a command that does nothing; if you +use this command after @code{@@table}, the first column entries are +output without added highlighting (``as is''). + +The @code{@@table} command works with other commands besides those +explicitly mentioned here. However, you can only use commands that +normally take arguments in braces. (In this case, however, you use +the command name without an argument, because the subsequent +@code{@@item}'s will supply the argument.) + +@findex item +Begin each table entry with an @code{@@item} command at the beginning +of a line. Write the first column text on the same line as the +@code{@@item} command. Write the second column text on the line +following the @code{@@item} line and on subsequent lines. (You do not +need to type anything for an empty second column entry.) You may +write as many lines of supporting text as you wish, even several +paragraphs. But only the text on the same line as the @code{@@item} +will be placed in the first column (including any footnotes). + +Normally, you should put a blank line before an @code{@@item} line. +This puts a blank line in the Info file. Except when the entries are +very brief, a blank line looks better. + +End the table with a line consisting of @code{@@end table}, followed +by a blank line. @TeX{} will always start a new paragraph after the +table, so the blank line is needed for the Info output to be analogous. + +@need 1500 +The following table, for example, highlights the text in the first +column with an @code{@@samp} command: + +@example +@group +@@table @@samp +@@item foo +This is the text for +@@samp@{foo@}. + +@@item bar +Text for @@samp@{bar@}. +@@end table +@end group +@end example + +@noindent +This produces: + +@table @samp +@item foo +This is the text for +@samp{foo}. +@item bar +Text for @samp{bar}. +@end table + +If you want to list two or more named items with a single block of +text, use the @code{@@itemx} command. (@xref{itemx,,@code{@@itemx}}.) + + +@node ftable vtable +@subsection @code{@@ftable} and @code{@@vtable} +@cindex Tables with indexes +@cindex Indexing table entries automatically +@findex ftable +@findex vtable + +The @code{@@ftable} and @code{@@vtable} commands are the same as the +@code{@@table} command except that @code{@@ftable} automatically enters +each of the items in the first column of the table into the index of +functions and @code{@@vtable} automatically enters each of the items in +the first column of the table into the index of variables. This +simplifies the task of creating indices. Only the items on the same +line as the @code{@@item} commands are indexed, and they are indexed in +exactly the form that they appear on that line. @xref{Indices}, +for more information about indices.@refill + +Begin a two-column table using @code{@@ftable} or @code{@@vtable} by +writing the @@-command at the beginning of a line, followed on the same +line by an argument that is a Texinfo command such as @code{@@code}, +exactly as you would for an @code{@@table} command; and end the table +with an @code{@@end ftable} or @code{@@end vtable} command on a line by +itself. + +See the example for @code{@@table} in the previous section. + +@node itemx +@subsection @code{@@itemx} +@cindex Two named items for @code{@@table} +@findex itemx + +Use the @code{@@itemx} command inside a table when you have two or more +first column entries for the same item, each of which should appear on a +line of its own. + +Use @code{@@item} for the first entry, and @code{@@itemx} for all +subsequent entries; @code{@@itemx} must always follow an @code{@@item} +command, with no blank line intervening. + +The @code{@@itemx} command works exactly like @code{@@item} except +that it does not generate extra vertical space above the first column +text. If you have multiple consecutive @code{@@itemx} commands, do +not insert any blank lines between them. + +For example, + +@example +@group +@@table @@code +@@item upcase +@@itemx downcase +These two functions accept a character or a string as +argument, and return the corresponding upper case (lower +case) character or string. +@@end table +@end group +@end example + +@noindent +This produces: + +@table @code +@item upcase +@itemx downcase +These two functions accept a character or a string as +argument, and return the corresponding upper case (lower +case) character or string.@refill +@end table + +@noindent +(Note also that this example illustrates multi-line supporting text in +a two-column table.)@refill + + +@node Multi-column Tables +@section @code{@@multitable}: Multi-column Tables +@cindex Tables, making multi-column +@findex multitable + +@code{@@multitable} allows you to construct tables with any number of +columns, with each column having any width you like. + +You define the column widths on the @code{@@multitable} line itself, and +write each row of the actual table following an @code{@@item} command, +with columns separated by an @code{@@tab} command. Finally, @code{@@end +multitable} completes the table. Details in the sections below. + +@menu +* Multitable Column Widths:: Defining multitable column widths. +* Multitable Rows:: Defining multitable rows, with examples. +@end menu + +@node Multitable Column Widths +@subsection Multitable Column Widths +@cindex Multitable column widths +@cindex Column widths, defining for multitables +@cindex Widths, defining multitable column + +You can define the column widths for a multitable in two ways: as +fractions of the line length; or with a prototype row. Mixing the two +methods is not supported. In either case, the widths are defined +entirely on the same line as the @code{@@multitable} command. + +@enumerate +@item +@findex columnfractions +@cindex Line length, column widths as fraction of +To specify column widths as fractions of the line length, write +@code{@@columnfractions} and the decimal numbers (presumably less than +1; a leading zero is allowed and ignored) after the +@code{@@multitable} command, as in: + +@example +@@multitable @@columnfractions .33 .33 .33 +@end example + +The fractions need not add up exactly to 1.0, as these do not. This +allows you to produce tables that do not need the full line length. + +@item +@cindex Prototype row, column widths defined by +To specify a prototype row, write the longest entry for each column +enclosed in braces after the @code{@@multitable} command. For example: + +@example +@@multitable @{some text for column one@} @{for column two@} +@end example + +@noindent +The first column will then have the width of the typeset `some text for +column one', and the second column the width of `for column two'. + +The prototype entries need not appear in the table itself. + +Although we used simple text in this example, the prototype entries can +contain Texinfo commands; markup commands such as @code{@@code} are +particularly likely to be useful. + +@end enumerate + + +@node Multitable Rows +@subsection Multitable Rows +@cindex Multitable rows +@cindex Rows, of a multitable + +@findex item +@findex tab +After the @code{@@multitable} command defining the column widths (see +the previous section), you begin each row in the body of a multitable +with @code{@@item}, and separate the column entries with @code{@@tab}. +Line breaks are not special within the table body, and you may break +input lines in your source file as necessary. + +@findex headitem +@cindex Heading row, in table +@cindex <thead> HTML tag +You can also use @code{@@headitem} instead of @code{@@item} to produce +a @dfn{heading row}. The @TeX{} output for such a row is in bold, and +the HTML, XML, and Docbook output uses the @code{<thead>} tag. In +Info, the heading row is followed by a separator line made of dashes +(@samp{-} characters). + +Here is a complete example of a multi-column table (the text is from +@cite{The GNU Emacs Manual}, @pxref{Split Window,, Splitting Windows, +emacs, The GNU Emacs Manual}): + +@example +@@multitable @@columnfractions .15 .45 .4 +@@headitem Key @@tab Command @@tab Description +@@item C-x 2 +@@tab @@code@{split-window-vertically@} +@@tab Split the selected window into two windows, +with one above the other. +@@item C-x 3 +@@tab @@code@{split-window-horizontally@} +@@tab Split the selected window into two windows +positioned side by side. +@@item C-Mouse-2 +@@tab +@@tab In the mode line or scroll bar of a window, +split that window. +@@end multitable +@end example + +@noindent produces: + +@multitable @columnfractions .15 .45 .4 +@headitem Key @tab Command @tab Description +@item C-x 2 +@tab @code{split-window-vertically} +@tab Split the selected window into two windows, +with one above the other. +@item C-x 3 +@tab @code{split-window-horizontally} +@tab Split the selected window into two windows +positioned side by side. +@item C-Mouse-2 +@tab +@tab In the mode line or scroll bar of a window, +split that window. +@end multitable + + +@node Special Displays +@chapter Special Displays +@cindex Special displays + +The commands in this chapter allow you to write text that is specially +displayed (output format permitting), outside of the normal document +flow. + +One set of such commands is for creating ``floats'', that is, figures, +tables, and the like, set off from the main text, possibly numbered, +captioned, and/or referred to from elsewhere in the document. Images +are often included in these displays. + +Another group of commands is for creating footnotes in Texinfo. + +@menu +* Floats:: Figures, tables, and the like. +* Images:: Including graphics and images. +* Footnotes:: Writing footnotes. +@end menu + + +@node Floats +@section Floats +@cindex Floats, in general + +A @dfn{float} is a display which is set off from the main text. It is +typically labelled as being a ``Figure'', ``Table'', ``Example'', or +some similar type. + +@cindex Floating, not yet implemented +A float is so-named because, in principle, it can be moved to the +bottom or top of the current page, or to a following page, in the +printed output. (Floating does not make sense in other output +formats.) In the present version of Texinfo, however, this floating +is unfortunately not yet implemented. Instead, the floating material +is simply output at the current location, more or less as if it were +an @code{@@group} (@pxref{group,,@code{@@group}}). + +@menu +* float:: Producing floating material. +* caption shortcaption:: Specifying descriptions for floats. +* listoffloats:: A table of contents for floats. +@end menu + + +@node float +@subsection @code{@@float} [@var{type}][,@var{label}]: Floating Material +@findex float +@cindex Float environment + +To produce floating material, enclose the material you want to be +displayed separate between @code{@@float} and @code{@@end float} +commands, on lines by themselves. + +Floating material uses @code{@@image} to display an already-existing +graphic (@pxref{Images}), or @code{@@multitable} to display a table +(@pxref{Multi-column Tables}). However, the contents of the float can +be anything. Here's an example with simple text: + +@example +@@float Figure,fig:ex1 +This is an example float. +@@end float +@end example + +@noindent And the output: + +@float Figure,fig:ex1 +This is an example float. +@end float + +As shown in the example, @code{@@float} takes two arguments (separated +by a comma), @var{type} and @var{label}. Both are optional. + +@table @var +@item type +Specifies the sort of float this is; typically a word such as +``Figure'', ``Table'', etc. If not given, and @var{label} is, any +cross-referencing will simply use a bare number. + +@item label +Specifies a cross-reference label for this float. If given, this +float is automatically given a number, and will appear in any +@code{@@listoffloats} output (@pxref{listoffloats}). Cross-references +to @var{label} are allowed. + +@cindex Floats, making unnumbered +@cindex Unnumbered float, creating +On the other hand, if @var{label} is not given, then the float will +not be numbered and consequently will not appear in the +@code{@@listoffloats} output or be cross-referenceable. +@end table + +@noindent Normally, you specify both @var{type} and @var{label}, to get a +labeled and numbered float. + +@cindex Floats, numbering of +@cindex Numbering of floats +In Texinfo, all floats are numbered the same way: with the chapter +number (or appendix letter), a period, and the float number, which +simply counts 1, 2, 3, @dots{}, and is reset at each chapter. Each +float type is counted independently. + +Floats within an @code{@@unnumbered} are numbered, or outside of any +chapter, are simply numbered consecutively from 1. + +These numbering conventions are not, at present, changeable. + + +@node caption shortcaption +@subsection @code{@@caption} & @code{@@shortcaption} +@findex caption +@findex shortcaption +@cindex Captions, for floats +@cindex Short captions, for lists of floats + +You may write an @code{@@caption} anywhere within a @code{@@float} +environment, to define a caption for the float. It is not allowed in +any other context. @code{@@caption} takes a single argument, enclosed +in braces. Here's an example: + +@example +@@float +An example float, with caption. +@@caption@{Caption for example float.@} +@@end float +@end example + +@noindent The output is: + +@float +An example float, with caption. +@caption{Caption for example float.} +@end float + +@code{@@caption} can appear anywhere within the float; it is not +processed until the @code{@@end float}. The caption text is usually a +sentence or two, but may consist of several paragraphs if necessary. + +In the output, the caption always appears below the float; this is not +currently changeable. It is preceded by the float type and/or number, +as specified to the @code{@@float} command (see the previous section). + +The @code{@@shortcaption} command likewise may be used only within +@code{@@float}, and takes a single argument in braces. The short +caption text is used instead of the caption text in a list of floats +(see the next section). Thus, you can write a long caption for the +main document, and a short title to appear in the list of floats. For +example: + +@example +@@float +... as above ... +@@shortcaption@{Text for list of floats.@} +@@end float +@end example + +The text for @code{@@caption} and @code{@@shortcaption} may not +contain comments (@code{@@c}), verbatim text (@code{@@verb}), +environments such as @code{@@example}, or other complex constructs. + + +@node listoffloats +@subsection @code{@@listoffloats}: Tables of Contents for Floats +@findex listoffloats +@cindex List of floats +@cindex Floats, list of +@cindex Table of contents, for floats + +You can write a @code{@@listoffloats} command to generate a list of +floats for a given float type (@pxref{float}), analogous to the +document's overall table of contents. Typically, it is written in its +own @code{@@unnumbered} node to provide a heading and structure, +rather like @code{@@printindex} (@pxref{Printing Indices & Menus}). + +@code{@@listoffloats} takes one optional argument, the float type. +Here's an example: + +@example +@@node List of Figures +@@unnumbered List of Figures +@@listoffloats Figure +@end example + +@noindent And the output from @code{@@listoffloats}: + +@display +@listoffloats Figure +@end display + +Without any argument, @code{@@listoffloats} generates a list of +floats for which no float type was specified, i.e., no first argument +to the @code{@@float} command (@pxref{float}). + +Each line in the list of floats contains the float type (if any), +the float number, and the caption, if any---the @code{@@shortcaption} +argument, if it was specified, else the @code{@@caption} argument. +In Info, the result is a menu where each float can be selected. In +HTML, each line is a link to the float. In printed output, the page +number is included. + +Unnumbered floats (those without cross-reference labels) are omitted +from the list of floats. + + +@node Images +@section Inserting Images + +@cindex Images, inserting +@cindex Pictures, inserting +@findex image + +You can insert an image given in an external file with the +@code{@@image} command. Although images can be used anywhere, +including the middle of a paragraph, we describe them in this chapter +since they are most often part of a displayed figure or example. + +@menu +* Image Syntax:: +* Image Scaling:: +@end menu + + +@node Image Syntax +@subsection Image Syntax + +Here is the synopsis of the @code{@@image} command: + +@example +@@image@{@var{filename}@r{[,} @var{width}@r{[,} @var{height}@r{[,} @var{alttext}@r{[, }@var{extension}@r{]]]]}@} +@end example + +@cindex Formats for images +@cindex Image formats +The @var{filename} argument is mandatory, and must not have an +extension, because the different processors support different formats: + +@itemize @bullet +@item +@pindex eps image format +@TeX{} reads the file @file{@var{filename}.eps} (Encapsulated PostScript +format). +@item +@pindex pdftex@r{, and images} +@pindex png image format +@pindex jpeg image format +@pindex pdf image inclusions +pdf@TeX{} reads @file{@var{filename}.png}, @file{@var{filename}.jpg}, +@file{@var{filename}.jpeg}, or @file{@var{filename}.pdf} (in that +order). It also tries uppercase versions of the extensions. The PDF +format cannot support EPS images, so they must be converted first. +@item +@code{makeinfo} includes @file{@var{filename}.txt} verbatim for +Info output (more or less as if it was an @code{@@example}). +@item +@code{makeinfo} uses the optional fifth argument @var{extension} to +@code{@@image} for the filename extension, if it is specified. For example: + +@pindex XPM image format +@example +@@image@{foo,,,,.xpm@} +@end example + +@noindent +will cause @code{makeinfo} to look for @file{foo.xpm} before any others. + +@end itemize + +The @var{width} and @var{height} arguments are described in the next +section. + +For @TeX{} output, if an image is the only thing in a paragraph it +will ordinarily be displayed on a line by itself, respecting the +current environment indentation, but without the normal paragraph +indentation. If you want it centered, use @code{@@center} +(@pxref{titlefont center sp,,@code{@@titlefont @@center @@sp}}). + +@cindex Alt attribute for images +@cindex Images, alternate text for +@findex - (in image alt string) +For HTML output, @code{makeinfo} sets the @dfn{alt attribute} for +inline images to the optional @var{alttext} (fourth) argument to +@code{@@image}, if supplied. If not supplied, @code{makeinfo} uses +the full file name of the image being displayed. The @var{alttext} is +taken as Texinfo text, so special characters such as @samp{"} and +@samp{<} and @samp{&} are escaped in the HTML and XML output; also, +you can get an empty @code{alt} string with @code{@@-} (a command +that produces no output; @pxref{- and hyphenation}). + +For Info output, the @code{alt} string is also processed as Texinfo +text and output. In this case, @samp{\} is escaped as @samp{\\} and +@samp{"} as @samp{\"}; no other escapes are done. + +@cindex PNG image format +@cindex JPEG image format +If you do not supply the optional @var{extension} (fifth) argument, +@code{makeinfo} first tries @file{@var{filename}.png}; if that does +not exist, it tries @file{@var{filename}.jpg}. If that does not exist +either, it complains. + +In Info output, @code{makeinfo} writes a reference to the binary image +file (trying @var{filename} suffixed with @file{@var{extension}}, +@file{@var{.extension}}, @file{.png}, or @file{.jpg}, in that order) +if one exists. It also literally includes the @file{.txt} file if one +exists. This way, Info readers which can display images (such as the +Emacs Info browser, running under X) can do so, whereas Info readers +which can only use text (such as the standalone Info reader) can +display the textual version. + +@cindex @samp{^@@^H} for images in Info +The implementation of this is to put the following construct into the +Info output: + +@example +^@@^H[image src="@var{binaryfile}" text="@var{txtfile}" + alt="@var{alttext} ... ^@@^H] +@end example + +@noindent where @samp{^@@} and @samp{^H} stand for the actual null and +backspace control characters. If one of the files is not present, the +corresponding argument is omitted. + +The reason for mentioning this here is that older Info browsers (this +feature was introduced in Texinfo version 4.6) will display the above +literally, which, although not pretty, should not be harmful. + + +@node Image Scaling +@subsection Image Scaling + +@cindex Images, scaling +@cindex Scaling images +@cindex Width of images +@cindex Height of images +@cindex Aspect ratio of images +@cindex Distorting images +The optional @var{width} and @var{height} arguments to the +@code{@@image} command (see the previous section) specify the size to +scale the image to. They are ignored for Info output. If neither is +specified, the image is presented in its natural size (given in the +file); if only one is specified, the other is scaled proportionately; +and if both are specified, both are respected, thus possibly distorting +the original image by changing its aspect ratio. + +@cindex Dimensions and image sizes +The @var{width} and @var{height} may be specified using any valid @TeX{} +dimension, namely: + +@table @asis +@item pt +@cindex Points (dimension) +point (72.27pt = 1in) +@item pc +@cindex Picas +pica (1pc = 12pt) +@item bp +@cindex Big points +big point (72bp = 1in) +@item in +@cindex Inches +inch +@item cm +@cindex Centimeters +centimeter (2.54cm = 1in) +@item mm +@cindex Millimeters +millimeter (10mm = 1cm) +@item dd +@cindex Did@^ot points +did@^ot point (1157dd = 1238pt) +@item cc +@cindex Ciceros +cicero (1cc = 12dd) +@item sp +@cindex Scaled points +scaled point (65536sp = 1pt) +@end table + +@pindex ridt.eps +For example, the following will scale a file @file{ridt.eps} to one +inch vertically, with the width scaled proportionately: + +@example +@@image@{ridt,,1in@} +@end example + +@pindex epsf.tex +For @code{@@image} to work with @TeX{}, the file @file{epsf.tex} must be +installed somewhere that @TeX{} can find it. (The standard location is +@file{@var{texmf}/tex/generic/dvips/epsf.tex}, where @var{texmf} is a +root of your @TeX{} directory tree.) This file is included in the +Texinfo distribution and is also available from +@uref{ftp://tug.org/tex/epsf.tex}, among other places. + +@code{@@image} can be used within a line as well as for displayed +figures. Therefore, if you intend it to be displayed, be sure to leave +a blank line before the command, or the output will run into the +preceding text. + +Image scaling is presently implemented only in @TeX{}, not in HTML or +any other sort of output. + + +@node Footnotes +@section Footnotes +@cindex Footnotes +@findex footnote + +A @dfn{footnote} is for a reference that documents or elucidates the +primary text.@footnote{A footnote should complement or expand upon +the primary text, but a reader should not need to read a footnote to +understand the primary text. For a thorough discussion of footnotes, +see @cite{The Chicago Manual of Style}, which is published by the +University of Chicago Press.} Footnotes are distracting; use them +sparingly, if at all. Standard bibliographical references are better +placed in a bibliography at the end of a document than in footnotes +throughout. + +@menu +* Footnote Commands:: How to write a footnote in Texinfo. +* Footnote Styles:: Controlling how footnotes appear in Info. +@end menu + + +@node Footnote Commands +@subsection Footnote Commands + +In Texinfo, footnotes are created with the @code{@@footnote} command. +This command is followed immediately by a left brace, then by the text +of the footnote, and then by a terminating right brace. Footnotes may +be of any length (they will be broken across pages if necessary), but +are usually short. The template is: + +@example +ordinary text@@footnote@{@var{text of footnote}@} +@end example + +As shown here, the @code{@@footnote} command should come right after the +text being footnoted, with no intervening space; otherwise, the footnote +marker might end up starting a line. + +For example, this clause is followed by a sample footnote@footnote{Here +is the sample footnote.}; in the Texinfo source, it looks like +this: + +@example +@dots{}a sample footnote@@footnote@{Here is the sample +footnote.@}; in the Texinfo source@dots{} +@end example + +As you can see, the source includes two punctuation marks next to each +other; in this case, @samp{.@};} is the sequence. This is normal (the +first ends the footnote and the second belongs to the sentence being +footnoted), so don't worry that it looks odd. + +In a printed manual or book, the reference mark for a footnote is a +small, superscripted number; the text of the footnote appears at the +bottom of the page, below a horizontal line. + +In Info, the reference mark for a footnote is a pair of parentheses +with the footnote number between them, like this: @samp{(1)}. The +reference mark is followed by a cross-reference link to the footnote's +text. + +In the HTML output, footnote references are marked with a small, +superscripted number which is rendered as a hypertext link to the +footnote text. + +By the way, footnotes in the argument of an @code{@@item} command for a +@code{@@table} must be on the same line as the @code{@@item} +(as usual). @xref{Two-column Tables}. + + +@node Footnote Styles +@subsection Footnote Styles + +Info has two footnote styles, which determine where the text of the +footnote is located: + +@itemize @bullet +@cindex @samp{@r{End}} node footnote style +@item +In the `End' node style, all the footnotes for a single node +are placed at the end of that node. The footnotes are separated from +the rest of the node by a line of dashes with the word +@samp{Footnotes} within it. Each footnote begins with an +@samp{(@var{n})} reference mark. + +@need 700 +@noindent +Here is an example of a single footnote in the end of node style:@refill + +@example +@group +--------- Footnotes --------- + +(1) Here is a sample footnote. +@end group +@end example + +@cindex @samp{@r{Separate}} footnote style +@item +In the `Separate' node style, all the footnotes for a single +node are placed in an automatically constructed node of +their own. In this style, a ``footnote reference'' follows +each @samp{(@var{n})} reference mark in the body of the +node. The footnote reference is actually a cross reference +which you use to reach the footnote node. + +The name of the node with the footnotes is constructed +by appending @w{@samp{-Footnotes}} to the name of the node +that contains the footnotes. (Consequently, the footnotes' +node for the @file{Footnotes} node is +@w{@file{Footnotes-Footnotes}}!) The footnotes' node has an +`Up' node pointer that leads back to its parent node. + +@noindent +Here is how the first footnote in this manual looks after being +formatted for Info in the separate node style: + +@smallexample +@group +File: texinfo.info Node: Overview-Footnotes, Up: Overview + +(1) The first syllable of "Texinfo" is pronounced like "speck", not +"hex". @dots{} +@end group +@end smallexample +@end itemize + +Unless your document has long and important footnotes (as in, say, +Gibbon's @cite{Decline and Fall @dots{}}), we recommend the @samp{end} +style, as it is simpler for readers to follow. + +@findex footnotestyle +Use the @code{@@footnotestyle} command to specify an Info file's +footnote style. Write this command at the beginning of a line followed +by an argument, either @samp{end} for the end node style or +@samp{separate} for the separate node style. + +@need 700 +For example, + +@example +@@footnotestyle end +@end example +@noindent +or +@example +@@footnotestyle separate +@end example + +Write an @code{@@footnotestyle} command before or shortly after the +end-of-header line at the beginning of a Texinfo file. (If you +include the @code{@@footnotestyle} command between the start-of-header +and end-of-header lines, the region formatting commands will format +footnotes as specified.)@refill + +If you do not specify a footnote style, the formatting commands use +their default style. Currently, @code{texinfo-format-buffer} and +@code{texinfo-format-region} use the `separate' style and +@code{makeinfo} uses the `end' style. + + +@node Indices +@chapter Indices +@cindex Indices + +Using Texinfo, you can generate indices without having to sort and +collate entries manually. In an index, the entries are listed in +alphabetical order, together with information on how to find the +discussion of each entry. In a printed manual, this information +consists of page numbers. In an Info file, this information is a menu +entry leading to the first node referenced. + +Texinfo provides several predefined kinds of index: an index +for functions, an index for variables, an index for concepts, and so +on. You can combine indices or use them for other than their +canonical purpose. Lastly, you can define your own new indices. + +@xref{Printing Indices & Menus}, for information on how to print +indices. + +@menu +* Index Entries:: Choose different words for index entries. +* Predefined Indices:: Use different indices for different kinds + of entries. +* Indexing Commands:: How to make an index entry. +* Combining Indices:: How to combine indices. +* New Indices:: How to define your own indices. +@end menu + + +@node Index Entries +@section Making Index Entries +@cindex Index entries, making +@cindex Entries, making index + +When you are making index entries, it is good practice to think of the +different ways people may look for something. Different people +@emph{do not} think of the same words when they look something up. A +helpful index will have items indexed under all the different words +that people may use. For example, one reader may think it obvious that +the two-letter names for indices should be listed under ``Indices, +two-letter names'', since the word ``Index'' is the general concept. +But another reader may remember the specific concept of two-letter +names and search for the entry listed as ``Two letter names for +indices''. A good index will have both entries and will help both +readers.@refill + +Like typesetting, the construction of an index is a highly skilled, +professional art, the subtleties of which are not appreciated until you +need to do it yourself.@refill + +@xref{Printing Indices & Menus}, for information about printing an index +at the end of a book or creating an index menu in an Info file.@refill + + +@node Predefined Indices +@section Predefined Indices + +Texinfo provides six predefined indices. Here are their nominal +meanings, abbreviations, and the corresponding index entry commands: + +@table @samp +@item cp +@cindex @code{cp} (concept) index +(@code{@@cindex}) concept index, for general concepts. +@item fn +@cindex @code{fn} (function) index +(@code{@@findex}) function index, for function and function-like +names (such as entry points of libraries). +@item ky +@cindex @code{ky} (keystroke) index +(@code{@@kindex}) keystroke index, for keyboard commands. +@item pg +@cindex @code{pg} (program) index +(@code{@@pindex}) program index, for names of programs. +@item tp +@cindex @code{tp} (data type) index +(@code{@@tindex}) data type index, for type names (such as structures +defined in header files). +@item vr +@cindex @code{vr} (variable) index +(@code{@@vindex}) variable index, for variable names (such as global +variables of libraries). +@end table + +@noindent +Not every manual needs all of these, and most manuals use only two or +three at most. The present manual, for example, has two indices: a +concept index and an @@-command index (that is actually the function +index but is called a command index in the chapter heading). + +You are not required to use the predefined indices strictly for their +canonical purposes. For example, suppose you wish to index some C +preprocessor macros. You could put them in the function index along +with actual functions, just by writing @code{@@findex} commands for +them; then, when you print the ``Function Index'' as an unnumbered +chapter, you could give it the title `Function and Macro Index' and +all will be consistent for the reader. + +On the other hand, it is best not to stray too far from the meaning of +the predefined indices. Otherwise, in the event that your text is +combined with other text from other manuals, the index entries will +not match up. Instead, define your own new index (@pxref{New +Indices}). + +We recommend having a single index in the final document whenever +possible, however many source indices you use, since then readers have +only one place to look. Two or more source indices can be combined +into one output index using the @code{@@synindex} or +@code{@@syncodeindex} commands (@pxref{Combining Indices}). + + +@node Indexing Commands +@section Defining the Entries of an Index +@cindex Defining indexing entries +@cindex Index entries +@cindex Entries for an index +@cindex Specifying index entries +@cindex Creating index entries + +The data to make an index come from many individual indexing commands +scattered throughout the Texinfo source file. Each command says to add +one entry to a particular index; after formatting, the index will give +the current page number or node name as the reference.@refill + +An index entry consists of an indexing command at the beginning of a +line followed, on the rest of the line, by the entry.@refill + +For example, this section begins with the following five entries for +the concept index:@refill + +@example +@@cindex Defining indexing entries +@@cindex Index entries, defining +@@cindex Entries for an index +@@cindex Specifying index entries +@@cindex Creating index entries +@end example + +Each predefined index has its own indexing command---@code{@@cindex} +for the concept index, @code{@@findex} for the function index, and so +on, as listed in the previous section. + +@cindex Writing index entries +@cindex Index entry writing +Concept index entries consist of text. The best way to write an index +is to choose entries that are terse yet clear. If you can do this, +the index often looks better if the entries are not capitalized, but +written just as they would appear in the middle of a sentence. +(Capitalize proper names and acronyms that always call for upper case +letters.) This is the case convention we use in most GNU manuals' +indices. + +If you don't see how to make an entry terse yet clear, make it longer +and clear---not terse and confusing. If many of the entries are several +words long, the index may look better if you use a different convention: +to capitalize the first word of each entry. But do not capitalize a +case-sensitive name such as a C or Lisp function name or a shell +command; that would be a spelling error. + +Whichever case convention you use, please use it consistently! + +Entries in indices other than the concept index are symbol names in +programming languages, or program names; these names are usually +case-sensitive, so use upper and lower case as required for them. + +@cindex Index font types +By default, entries for a concept index are printed in a small roman +font and entries for the other indices are printed in a small +@code{@@code} font. You may change the way part of an entry is +printed with the usual Texinfo commands, such as @code{@@file} for +file names (@pxref{Marking Text}), and @code{@@r} for the normal roman +font (@pxref{Fonts}). + +@quotation Caution +Do not use a colon in an index entry. In Info, a colon separates the +menu entry name from the node name, so a colon in the entry itself +confuses Info. @xref{Menu Parts}, for more information about the +structure of a menu entry. +@end quotation + + +@node Combining Indices +@section Combining Indices +@cindex Combining indices +@cindex Indices, combining them + +Sometimes you will want to combine two disparate indices such as +functions and concepts, perhaps because you have few enough entries +that a separate index would look silly. + +You could put functions into the concept index by writing +@code{@@cindex} commands for them instead of @code{@@findex} commands, +and produce a consistent manual by printing the concept index with the +title `Function and Concept Index' and not printing the `Function +Index' at all; but this is not a robust procedure. It works only if +your document is never included as part of another document that is +designed to have a separate function index; if your document were to +be included with such a document, the functions from your document and +those from the other would not end up together. Also, to make your +function names appear in the right font in the concept index, you +would need to enclose every one of them between the braces of +@code{@@code}. + +@menu +* syncodeindex:: How to merge two indices, using @code{@@code} + font for the merged-from index. +* synindex:: How to merge two indices, using the + default font of the merged-to index. +@end menu + +@node syncodeindex +@subsection @code{@@syncodeindex} +@findex syncodeindex + +When you want to combine functions and concepts into one index, you +should index the functions with @code{@@findex} and index the concepts +with @code{@@cindex}, and use the @code{@@syncodeindex} command to +redirect the function index entries into the concept index.@refill + +The @code{@@syncodeindex} command takes two arguments; they are the name +of the index to redirect, and the name of the index to redirect it to. +The template looks like this:@refill + +@example +@@syncodeindex @var{from} @var{to} +@end example + +@cindex Predefined names for indices +@cindex Two letter names for indices +@cindex Indices, two letter names +@cindex Names for indices +For this purpose, the indices are given two-letter names:@refill + +@table @samp +@item cp +concept index +@item fn +function index +@item vr +variable index +@item ky +key index +@item pg +program index +@item tp +data type index +@end table + +Write an @code{@@syncodeindex} command before or shortly after the +end-of-header line at the beginning of a Texinfo file. For example, +to merge a function index with a concept index, write the +following:@refill + +@example +@@syncodeindex fn cp +@end example + +@noindent +This will cause all entries designated for the function index to merge +in with the concept index instead.@refill + +To merge both a variables index and a function index into a concept +index, write the following:@refill + +@example +@group +@@syncodeindex vr cp +@@syncodeindex fn cp +@end group +@end example + +@cindex Fonts for indices +The @code{@@syncodeindex} command puts all the entries from the `from' +index (the redirected index) into the @code{@@code} font, overriding +whatever default font is used by the index to which the entries are +now directed. This way, if you direct function names from a function +index into a concept index, all the function names are printed in the +@code{@@code} font as you would expect.@refill + +@node synindex +@subsection @code{@@synindex} +@findex synindex + +The @code{@@synindex} command is nearly the same as the +@code{@@syncodeindex} command, except that it does not put the +`from' index entries into the @code{@@code} font; rather it puts +them in the roman font. Thus, you use @code{@@synindex} when you +merge a concept index into a function index.@refill + +@xref{Printing Indices & Menus}, for information about printing an index +at the end of a book or creating an index menu in an Info file.@refill + + +@node New Indices +@section Defining New Indices +@cindex Defining new indices +@cindex Indices, defining new +@cindex New index defining +@findex defindex +@findex defcodeindex + +In addition to the predefined indices, you may use the +@code{@@defindex} and @code{@@defcodeindex} commands to define new +indices. These commands create new indexing @@-commands with which +you mark index entries. The @code{@@defindex} command is used like +this: + +@example +@@defindex @var{name} +@end example + +The name of an index should be a two letter word, such as @samp{au}. +For example: + +@example +@@defindex au +@end example + +This defines a new index, called the @samp{au} index. At the same +time, it creates a new indexing command, @code{@@auindex}, that you +can use to make index entries. Use this new indexing command just as +you would use a predefined indexing command. + +For example, here is a section heading followed by a concept index +entry and two @samp{au} index entries. + +@example +@@section Cognitive Semantics +@@cindex kinesthetic image schemas +@@auindex Johnson, Mark +@@auindex Lakoff, George +@end example + +@noindent +(Evidently, @samp{au} serves here as an abbreviation for ``author''.) + +In general, Texinfo constructs the new indexing command by +concatenating the name of the index with @samp{index}; thus, defining +an @samp{xy} index leads to the automatic creation of an +@code{@@xyindex} command. + +Use the @code{@@printindex} command to print the index, as you do with +the predefined indices. For example: + +@example +@group +@@node Author Index +@@unnumbered Author Index + +@@printindex au +@end group +@end example + +The @code{@@defcodeindex} is like the @code{@@defindex} command, +except that, in the printed output, it prints entries in an +@code{@@code} font by default instead of a roman font. + +You should define new indices before the end-of-header line of a +Texinfo file, and (of course) before any @code{@@synindex} or +@code{@@syncodeindex} commands (@pxref{Texinfo File Header}). + + +@node Insertions +@chapter Special Insertions +@cindex Inserting special characters and symbols +@cindex Special insertions + +Texinfo provides several commands for inserting characters that have +special meaning in Texinfo, such as braces, and for other graphic +elements that do not correspond to simple characters you can type. + +@iftex +These are: + +@itemize @bullet +@item @samp{@@} and braces and commas. +@item Whitespace within and around a sentence. +@item Accents. +@item Dots and bullets. +@item The @TeX{} logo and the copyright symbol. +@item The euro and pounds currency symbols. +@item The degrees symbol. +@item The minus sign. +@item Mathematical expressions. +@item Glyphs for evaluation, macros, errors, etc. +@item Footnotes. +@item Images. +@end itemize +@end iftex + +@menu +* Atsign Braces Comma:: Inserting @@ and @{@} and ,. +* Inserting Quote Characters:: Inserting left and right quotes, in code. +* Inserting Space:: How to insert the right amount of space + within a sentence. +* Inserting Accents:: How to insert accents and special characters. +* Inserting Quotation Marks:: How to insert quotation marks. +* Dots Bullets:: How to insert dots and bullets. +* TeX and copyright:: How to insert the @TeX{} logo + and the copyright symbol. +* euro:: How to insert the Euro currency symbol. +* pounds:: How to insert the pounds currency symbol. +* textdegree:: How to insert the degrees symbol. +* minus:: How to insert a minus sign. +* geq leq:: How to insert greater/less-than-or-equal signs. +* math:: How to format a mathematical expression. +* Click Sequences:: Inserting GUI usage sequences. +* Glyphs:: How to indicate results of evaluation, + expansion of macros, errors, etc. +@end menu + + +@node Atsign Braces Comma +@section Inserting @@ and @{@} and @comma{} +@cindex Special characters, inserting +@cindex Commands to insert special characters + +@samp{@@} and curly braces are special characters in Texinfo. To insert +these characters so they appear in text, you must put an @samp{@@} in +front of these characters to prevent Texinfo from misinterpreting +them. + +The comma `,' is a special character only in one uncommon context: +it separates arguments to commands that take multiple arguments. + +@menu +* Inserting an Atsign:: +* Inserting Braces:: +* Inserting a Comma:: +@end menu + + +@node Inserting an Atsign +@subsection Inserting `@@' with @code{@@@@} +@findex @@ @r{(literal @samp{@@})} +@cindex Inserting @@ @r{(literal @samp{@@})} + +@code{@@@@} stands for a single @samp{@@} in either printed or Info +output. + +Do not put braces after an @code{@@@@} command. + + +@node Inserting Braces +@subsection Inserting `@{' and `@}' with @code{@@@{} and @code{@@@}} +@cindex Braces, inserting +@findex @{ @r{(literal @samp{@{})} +@findex @} @r{(literal @samp{@}})} + +@code{@@@{} stands for a single @samp{@{} in either printed or Info +output. + +@code{@@@}} stands for a single @samp{@}} in either printed or Info +output. + +Do not put braces after either an @code{@@@{} or an @code{@@@}} +command. + + +@node Inserting a Comma +@subsection Inserting `,' with @code{@@comma@{@}} +@cindex Commas, inserting +@findex comma + +Ordinarily, a comma `,' is a normal character that can be simply typed +in your input where you need it. + +However, Texinfo uses the comma as a special character in one uncommon +context: some commands, such as @code{@@acronym} (@pxref{acronym}) and +@code{@@xref} (@pxref{Cross References}), as well as user-defined +macros (@pxref{Defining Macros}), can take more than one argument. In +these cases, the comma character is used to separate arguments. + +Since a comma character would confuse Texinfo's parsing for these +commands, you must use the command @samp{@@comma@{@}} instead if you want +to pass an actual comma. Here are some examples: + +@example +@@acronym@{ABC, A Bizarre @@comma@{@}@} +@@xref@{Comma,, The @@comma@{@} symbol@} +@@mymac@{One argument@@comma@{@} containing a comma@} +@end example + +Although @comma{} can be used nearly anywhere, there is no need for it +anywhere except in this unusual case. + + +@node Inserting Quote Characters +@section Inserting Quote Characters + +@cindex Inserting quote characters +@cindex Quote characters, inserting + +As explained in the early section on general Texinfo input conventions +(@pxref{Conventions}), Texinfo source files use the ASCII character +@code{`} (96 decimal) to produce a left quote (`), and ASCII @code{'} +(39 decimal) to produce a right quote ('). Doubling these input +characters (@code{``} and @code{''}) produces double quotes (`` and +''). These are the conventions used by @TeX{}. + +This works all right for text. However, in examples of computer code, +readers are especially likely to cut and paste the text +verbatim---and, unfortunately, some document viewers will mangle these +characters. (The free PDF reader @command{xpdf} works fine, but other +PDF readers, both free and nonfree, have problems.) + +If this is a concern for your document, Texinfo provides two special +settings via @code{@@set}: + +@table @code +@item @@set txicodequoteundirected +causes the output for the @code{'} character to be the undirected +single quote, like this: +@set txicodequoteundirected +@code{'}. +@clear txicodequoteundirected + +@item @@set txicodequotebacktick +Cause the output for the @code{`} character to be the standalone grave +accent, like this: +@set txicodequotebacktick +@code{`}. +@clear txicodequotebacktick + +@end table + +@code{xyza`'bc} + +If you want these settings for only part of the document, +@code{@@clear} will restore the normal behavior, as in +@code{@@clear@tie{}txicodequoteundirected}. + +These settings affect @code{@@code}, @code{@@example}, and +@code{@@verbatim}; they do not affect @code{@@samp}. (@xref{Useful +Highlighting}.) + + +@node Inserting Space +@section Inserting Space + +@cindex Inserting space +@cindex Spacing, inserting +The following sections describe commands that control spacing of various +kinds within and after sentences. + +@menu +* Not Ending a Sentence:: Sometimes a . doesn't end a sentence. +* Ending a Sentence:: Sometimes it does. +* Multiple Spaces:: Inserting multiple spaces. +* frenchspacing:: Specifying end-of-sentence spacing. +* dmn:: How to format a dimension. +@end menu + + +@node Not Ending a Sentence +@subsection Not Ending a Sentence + +@cindex Not ending a sentence +@cindex Sentence non-ending punctuation +@cindex Periods, inserting +Depending on whether a period or exclamation point or question mark is +inside or at the end of a sentence, less or more space is inserted after +a period in a typeset manual. Since it is not always possible +to determine when a period ends a sentence and when it is used +in an abbreviation, special commands are needed in some circumstances. +Usually, Texinfo can guess how to handle periods, so you do not need to +use the special commands; you just enter a period as you would if you +were using a typewriter, which means you put two spaces after the +period, question mark, or exclamation mark that ends a sentence. + +@findex <colon> @r{(suppress end-of-sentence space)} +Use the @code{@@:}@: command after a period, question mark, +exclamation mark, or colon that should not be followed by extra space. +For example, use @code{@@:}@: after periods that end abbreviations +which are not at the ends of sentences. + +For example, + +@example +foo vs.@@: bar +foo vs. bar +@end example + +@noindent +@ifnottex +produces +@end ifnottex +@iftex +produces the following. If you look carefully at this printed output, +you will see a little extraneous space after @samp{vs.}@: in the second +line. +@end iftex + +@quotation +foo vs.@: bar @* +foo vs. bar +@end quotation + +@noindent +@code{@@:} has no effect on the Info and HTML output. In Docbook and +XML, the previous punctuation character (.?!:) is output as an entity +instead of as the normal character: @samp{. ? ! +:}. This gives further processors a chance to notice and not +add the usual extra space. + +Do not put braces after @code{@@:} (or any non-alphabetic command). + + +@node Ending a Sentence +@subsection Ending a Sentence + +@cindex Ending a Sentence +@cindex Sentence ending punctuation + +@findex . @r{(end of sentence)} +@findex ! @r{(end of sentence)} +@findex ? @r{(end of sentence)} +Use @code{@@.}@: instead of a period, @code{@@!}@: instead of an +exclamation point, and @code{@@?}@: instead of a question mark at the end +of a sentence that ends with a capital letter. Otherwise, @TeX{} +will think the letter is an abbreviation and will not insert the correct +end-of-sentence spacing. Here is an example: + +@example +Give it to M.I.B. and to M.E.W@@. Also, give it to R.J.C@@. +Give it to M.I.B. and to M.E.W. Also, give it to R.J.C. +@end example + +@noindent +@ifnottex +produces +@end ifnottex +@iftex +produces the following. If you look carefully at this printed output, +you will see a little more whitespace after the @samp{W} in the first +line. +@end iftex + +@quotation +Give it to M.I.B. and to M.E.W@. Also, give it to R.J.C@.@* +Give it to M.I.B. and to M.E.W. Also, give it to R.J.C. +@end quotation + +In the Info file output, @code{@@.}@: is equivalent to a simple +@samp{.}; likewise for @code{@@!}@: and @code{@@?}@:. + +The meanings of @code{@@:} and @code{@@.}@: in Texinfo are designed to +work well with the Emacs sentence motion commands (@pxref{Sentences,,, +emacs, The GNU Emacs Manual}). + +Do not put braces after any of these commands. + + +@node Multiple Spaces +@subsection Multiple Spaces + +@cindex Multiple spaces +@cindex Whitespace, inserting +@cindex Space, inserting horizontal +@findex <space> +@findex <tab> +@findex <newline> + +Ordinarily, @TeX{} collapses multiple whitespace characters (space, tab, +and newline) into a single space. Info output, on the other hand, +preserves whitespace as you type it, except for changing a newline into +a space; this is why it is important to put two spaces at the end of +sentences in Texinfo documents. + +Occasionally, you may want to actually insert several consecutive +spaces, either for purposes of example (what your program does with +multiple spaces as input), or merely for purposes of appearance in +headings or lists. Texinfo supports three commands: +@code{@@@kbd{SPACE}}, @code{@@@kbd{TAB}}, and @code{@@@kbd{NL}}, all of +which insert a single space into the output. (Here, +@code{@@@kbd{SPACE}} represents an @samp{@@} character followed by a +space, i.e., @samp{@@ }, and @kbd{TAB} and @kbd{NL} represent the tab +character and end-of-line, i.e., when @samp{@@} is the last character on +a line.) + +For example, +@example +Spacey@@ @@ @@ @@ +example. +@end example + +@noindent produces + +@example +Spacey@ @ @ @ +example. +@end example + +Other possible uses of @code{@@@kbd{SPACE}} have been subsumed by +@code{@@multitable} (@pxref{Multi-column Tables}). + +Do not follow any of these commands with braces. + +To produce a non-breakable space, see @ref{tie, @code{@@tie}}. + + +@node frenchspacing +@subsection @code{@@frenchspacing} @var{val}: Control sentence spacing +@findex frenchspacing +@cindex French spacing +@cindex Sentences, spacing after +@cindex Space, after sentences + +In American typography, it is traditional and correct to put extra +space at the end of a sentence, after a semi-colon, and so on. This +is the default in Texinfo. In French typography (and many others), +this extra space is wrong; all spaces are uniform. + +Therefore Texinfo provides the @code{@@frenchspacing} command to +control the spacing after punctuation. It reads the rest of the line +as its argument, which must be the single word @samp{on} or @samp{off} +(always these words, regardless of the language) of the document. +Here is an example: + +@example +@@frenchspacing on +This is text. Two sentences. Three sentences. French spacing. + +@@frenchspacing off +This is text. Two sentences. Three sentences. Non-French spacing. +@end example + +@noindent produces (there will be no difference in Info): + +@frenchspacing on +This is text. Two sentences. Three sentences. French spacing. + +@frenchspacing off +This is text. Two sentences. Three sentences. Non-French spacing. + +@code{@@frenchspacing} mainly affects the printed output, including +the output after @code{@@.}, @code{@@!}, and @code{@@?} (@pxref{Ending +a Sentence}). + +In Info, usually space characters in the input are written unaltered +to the output, and @code{@@frenchspacing} does not change this. It +does change the one case where @command{makeinfo} outputs a space on +its own: when a sentence ends at a newline in the source. Here's an +example: + +@example +Some sentence. +Next sentence. +@end example + +@noindent produces in Info output, with @code{@@frenchspacing off} +(the default), two spaces between the sentences: + +@example +Some sentence. Next sentence. +@end example + +@noindent With @code{@@frenchspacing on}, @command{makeinfo} outputs +only a single space: + +@example +Some sentence. Next sentence. +@end example + +@code{@@frenchspacing} has no effect on the HTML or Docbook output; +for XML, it outputs a transliteration of itself (@pxref{Output +Formats}). + + +@node dmn +@subsection @code{@@dmn}@{@var{dimension}@}: Format a Dimension +@cindex Thin space between number, dimension +@cindex Dimension formatting +@cindex Format a dimension +@findex dmn + +At times, you may want to write @samp{12@dmn{pt}} or +@samp{8.5@dmn{in}} with little or no space between the number and the +abbreviation for the dimension. You can use the @code{@@dmn} command +to do this. On seeing the command, @TeX{} inserts just enough space +for proper typesetting; the Info formatting commands insert no space +at all, since the Info file does not require it. + +To use the @code{@@dmn} command, write the number and then follow it +immediately, with no intervening space, by @code{@@dmn}, and then by +the dimension within braces. For example, + +@example +A4 paper is 8.27@@dmn@{in@} wide. +@end example + +@noindent +produces + +@quotation +A4 paper is 8.27@dmn{in} wide. +@end quotation + +Not everyone uses this style. Some people prefer @w{@samp{8.27 in.@@:}} +or @w{@samp{8.27 inches}} to @samp{8.27@@dmn@{in@}} in the Texinfo file. +In these cases, however, the formatters may insert a line break between +the number and the dimension, so use @code{@@w} (@pxref{w}). Also, if +you write a period after an abbreviation within a sentence, you should +write @samp{@@:} after the period to prevent @TeX{} from inserting extra +whitespace, as shown here. @xref{Not Ending a Sentence}. + + +@node Inserting Accents +@section Inserting Accents + +@cindex Inserting accents +@cindex Accents, inserting +@cindex Floating accents, inserting + +Here is a table with the commands Texinfo provides for inserting +floating accents. They all need an argument, the character to accent, +which can either be given in braces as usual (@code{@@'@{e@}}), or, as +a special case, the braces can be omitted, in which case the argument +is the next character (@code{@@'e}). This is to make the source as +convenient as possible to type and read, since accented characters are +very common in some languages. + +If the command is alphabetic, such as @code{@@dotaccent}, then there +must be a space between the command name and argument if braces are +not used. If the command is non-alphabetic, such as @code{@@'}, then +there must @emph{not} be a space; the argument is the very next +character. + +Exception: the argument to @code{@@tieaccent} must be enclosed in +braces (since it is two characters instead of one). + +@findex documentencoding +To get the true accented characters output in Info, not just the ASCII +transliterations, it is necessary to specify @code{@@documentencoding} +with an encoding which supports the required characters +(@pxref{documentencoding,,@code{@@documentencoding}}). In this case, +you can also use non-ASCII (e.g., pre-accented) characters in the +source file. + +@findex " @r{(umlaut accent)} +@cindex Umlaut accent +@findex ' @r{(umlaut accent)} +@cindex Acute accent +@findex = @r{(macron accent)} +@cindex Macron accent +@findex ^ @r{(circumflex accent)} +@cindex Circumflex accent +@findex ` @r{(grave accent)} +@cindex Grave accent +@findex ~ @r{(tilde accent)} +@cindex Tilde accent +@findex , @r{(cedilla accent)} +@cindex Cedilla accent +@findex dotaccent +@cindex Dot accent +@findex H @r{(Hungarian umlaut accent)} +@cindex Hungarian umlaut accent +@findex ringaccent +@cindex Ring accent +@findex tieaccent +@cindex Tie-after accent +@findex u @r{(breve accent)} +@cindex Breve accent +@findex ubaraccent +@cindex Underbar accent +@findex udotaccent +@cindex Underdot accent +@findex v @r{(check accent)} +@cindex Hacek accent +@cindex Check accent +@cindex Caron accent +@multitable {@t{@@questiondown@{@}}} {Output} {hacek/check/caron accent} +@headitem Command @tab Output @tab What +@item @t{@@"o} @tab @"o @tab umlaut accent +@item @t{@@'o} @tab @'o @tab acute accent +@item @t{@@,@{c@}} @tab @,{c} @tab cedilla accent +@item @t{@@=o} @tab @=o @tab macron/overbar accent +@item @t{@@^o} @tab @^o @tab circumflex accent +@item @t{@@`o} @tab @`o @tab grave accent +@item @t{@@~o} @tab @~o @tab tilde accent +@item @t{@@dotaccent@{o@}} @tab @dotaccent{o} @tab overdot accent +@item @t{@@H@{o@}} @tab @H{o} @tab long Hungarian umlaut +@item @t{@@ringaccent@{o@}} @tab @ringaccent{o} @tab ring accent +@item @t{@@tieaccent@{oo@}} @tab @tieaccent{oo} @tab tie-after accent +@item @t{@@u@{o@}} @tab @u{o} @tab breve accent +@item @t{@@ubaraccent@{o@}} @tab @ubaraccent{o} @tab underbar accent +@item @t{@@udotaccent@{o@}} @tab @udotaccent{o} @tab underdot accent +@item @t{@@v@{o@}} @tab @v{o} @tab hacek/check/caron accent +@end multitable + +This table lists the Texinfo commands for inserting other characters +commonly used in languages other than English. + +@findex questiondown +@cindex @questiondown{} +@findex exclamdown +@cindex @exclamdown{} +@findex aa +@cindex @aa{} +@findex AA +@cindex @AA{} +@findex ae +@cindex @ae{} +@findex AE +@cindex @AE{} +@findex dotless +@cindex @dotless{i} (dotless i) +@cindex @dotless{j} (dotless j) +@cindex Dotless i, j +@findex l +@cindex @l{} +@findex L +@cindex @L{} +@findex o +@cindex @o{} +@findex O +@cindex @O{} +@findex oe +@cindex @oe{} +@findex OE +@cindex @OE{} +@cindex Romance ordinals +@cindex Ordinals, Romance +@cindex Feminine ordinal +@findex ordf +@cindex @ordf{} +@cindex Masculine ordinal +@findex ordm +@cindex @ordm{} +@findex ss +@cindex @ss{} +@cindex Es-zet +@cindex Sharp S +@cindex German S +@multitable {@t{@@questiondown@{@}}} {oe OE} {es-zet or sharp S} +@item @t{@@exclamdown@{@}} @tab @exclamdown{} @tab upside-down ! +@item @t{@@questiondown@{@}} @tab @questiondown{} @tab upside-down ? +@item @t{@@aa@{@} @@AA@{@}} @tab @aa{} @AA{} @tab a,A with circle +@item @t{@@ae@{@} @@AE@{@}} @tab @ae{} @AE{} @tab ae,AE ligatures +@item @t{@@dotless@{i@}} @tab @dotless{i} @tab dotless i +@item @t{@@dotless@{j@}} @tab @dotless{j} @tab dotless j +@item @t{@@l@{@} @@L@{@}} @tab @l{} @L{} @tab suppressed-L,l +@item @t{@@o@{@} @@O@{@}} @tab @o{} @O{} @tab O,o with slash +@item @t{@@oe@{@} @@OE@{@}} @tab @oe{} @OE{} @tab oe,OE ligatures +@item @t{@@ordf@{@} @@ordm@{@}} @tab @ordf{} @ordm{} @tab Spanish ordinals +@item @t{@@ss@{@}} @tab @ss{} @tab es-zet or sharp S +@end multitable + + +@node Inserting Quotation Marks +@section Inserting Quotation Marks +@cindex Inserting quotation marks +@cindex Quotation marks, inserting + +@cindex Quotation characters (`'), in source +Use doubled single-quote characters to begin and end quotations: +@w{@t{`@w{}`@dots{}'@w{}'}}. @TeX{} converts two single quotes to +left- and right-hand doubled quotation marks, +@c this comes out as "like this" in Info, which is just confusing. +@iftex +``like this'', +@end iftex +and Info converts doubled single-quote characters to ASCII +double-quotes: @w{@t{`@w{}`@dots{}'@w{}'}} becomes @w{@t{"@dots{}"}}. + +You may occasionally need to produce two consecutive single quotes; +for example, in documenting a computer language such as Maxima where +@t{'@w{}'} is a valid command. You can do this with the input +@t{'@@w@{@}'}; the empty @code{@@w} command stops the combination into +the double-quote characters. + +@cindex Unicode quotation characters +@cindex Grave accent, vs. left quote +The left quote character (@t{`}, ASCII code 96) used in Texinfo is a +grave accent in ANSI and ISO character set standards. We use it as a +quote character because that is how @TeX{} is set up, by default. + +Texinfo supports several other quotation marks used in languages other +than English. Below is a table with the commands Texinfo provides for +inserting quotation marks. + +@findex documentencoding +@cindex UTF-8 +@cindex ISO 8859-15 +@cindex Latin 9 +@cindex ISO 8859-1 +@cindex Latin 1 +In order to get the symbols for the quotation marks in encoded Info +output, it is necessary to specify @code{@@documentencoding UTF-8}. +(@xref{documentencoding,,@code{@@documentencoding}}.) Double +guillemets are also present in ISO 8859-1 (aka Latin@tie{}1) and ISO +8859-15 (aka Latin@tie{}9). + +@cindex European Computer Modern fonts +@cindex EC fonts +The standard @TeX{} fonts support the usual quotation marks used in +English (the ones produced with single and doubled ASCII +single-quotes). For the other quotation marks, @TeX{} uses European +Computer Modern (EC) fonts (@file{ecrm1000} and other variants). +These fonts are freely available, of course; you can download them +from @url{http://@/www.ctan.org/@/tex-archive/@/fonts/ec}, among other +places. + +@cindex CM-Super fonts +The free EC fonts are bitmap fonts created with Metafont. Especially +for on-line viewing, Type@tie{}1 (vector) versions of the fonts are +preferable; these are available in the CM-Super font package +(@url{http://@/www.ctan.org/@/tex-archive/@/fonts/@/ps-type1/@/cm-super}). + +Both distributions include installation instructions. + +@cindex Single quotation marks +@cindex Double quotation marks +@cindex Left quotation marks +@cindex Right quotation marks +@findex quotedblleft +@cindex `` +@findex quoteleft +@cindex ` +@findex quotedblright +@cindex '' +@findex quoteright +@cindex ' +@cindex Double low-9 quotation mark +@cindex Single low-9 quotation mark +@findex quotedblbase +@cindex @quotedblbase{} (double low-9 quotation mark) +@findex quotesinglbase +@cindex @quotesinglbase{} (single low-9 quotation mark) +@cindex Angle quotation marks +@cindex Guillemets +@cindex Guillemots +@cindex French quotation marks +@cindex Quotation marks, French +@cindex German quotation marks +@cindex Quotation marks, German +@cindex Double guillemets +@cindex Single guillemets +@cindex Double angle quotation marks +@cindex Single angle quotation marks +@cindex Left-pointing angle quotation marks +@cindex Right-pointing angle quotation marks +@cindex Double left-pointing angle quotation mark +@cindex Double right-pointing angle quotation mark +@cindex Single left-pointing angle quotation mark +@cindex Single right-pointing angle quotation mark +@findex guillemetleft +@findex guillemotleft +@cindex @guillemetleft{} +@findex guillemetright +@findex guillemotright +@cindex @guillemetright{} +@findex guilsinglleft +@cindex @guilsinglleft{} +@findex guilsinglright +@cindex @guilsinglright{} +@multitable {@t{@@quotedblright@{@} '@w{}'}} {Glyph} {Right-pointing double angle quotation mark (U+00BB)} +@headitem Command @tab Glyph @tab Unicode name (point) +@item @verb{.@quotedblleft{} ``.} @tab @quotedblleft{} @tab Left double quotation mark (U+201C) +@item @verb{.@quotedblright{} ''.} @tab @quotedblright{} @tab Right double quotation mark (U+201D) +@item @verb{.@quoteleft{} `.} @tab @quoteleft{} @tab Left single quotation mark (U+2018) +@item @verb{.@quoteright{} '.} @tab @quoteright{} @tab Right single quotation mark (U+2019) +@item @t{@@quotedblbase@{@}} @tab @quotedblbase{} @tab Double low-9 quotation mark (U+201E) +@item @t{@@quotesinglbase@{@}} @tab @quotesinglbase{} @tab Single low-9 quotation mark (U+201A) +@item @t{@@guillemetleft@{@}} @tab @guillemetleft{} @tab Left-pointing double angle quotation mark (U+00AB) +@item @t{@@guillemetright@{@}} @tab @guillemetright{} @tab Right-pointing double angle quotation mark (U+00BB) +@item @t{@@guilsinglleft@{@}} @tab @guilsinglleft{} @tab Single left-pointing angle quotation mark (U+2039) +@item @t{@@guilsinglright@{@}} @tab @guilsinglright{} @tab Single right-pointing angle quotation mark (U+203A) +@end multitable + +For the double angle quotation marks, Adobe and @LaTeX{} glyph names +are also supported: @code{@@guillemotleft} and +@code{@@guillemotright}. These names are actually incorrect; a +``guillemot'' is a bird species (a type of auk). + +Traditions for quotation mark usage vary to a great extent between +languages (@url{http://@/en.wikipedia.org/@/wiki/@/Quotation_mark%2C_non-English_usage@/#Overview}). +Texinfo does not provide commands for typesetting quotation marks +according to the numerous traditions. Therefore, you have to choose +the commands appropriate for the language of your manual. Sometimes +aliases (@pxref{alias,,@code{@@alias}}) can simplify the usage and +make the source code more readable. For example, in German, +@code{@@quotedblbase} is used for the left double quote, and the right +double quote is actually @code{@@quotedblleft}, which is +counter-intuitive. Thus, in this case the following aliases would be +convenient: + +@example +@@alias lgqq = quotedblbase +@@alias rgqq = quotedblleft +@end example + + +@node Dots Bullets +@section Inserting Ellipsis and Bullets +@cindex Dots, inserting +@cindex Bullets, inserting +@cindex Ellipsis, inserting +@cindex Inserting ellipsis +@cindex Inserting dots +@cindex Special typesetting commands +@cindex Typesetting commands for dots, etc. + +An @dfn{ellipsis} (a line of dots) is not typeset as a string of +periods, so a special command is used for ellipsis in Texinfo. The +@code{@@bullet} command is special, too. Each of these commands is +followed by a pair of braces, @samp{@{@}}, without any whitespace +between the name of the command and the braces. (You need to use braces +with these commands because you can use them next to other text; without +the braces, the formatters would be confused. @xref{Command Syntax, , +@@-Command Syntax}, for further information.)@refill + +@menu +* dots:: How to insert dots @dots{} +* bullet:: How to insert a bullet. +@end menu + + +@node dots +@subsection @code{@@dots}@{@} (@dots{}) and @code{@@enddots}@{@} (@enddots{}) +@findex dots +@findex enddots +@cindex Inserting dots +@cindex Dots, inserting + +Use the @code{@@dots@{@}} command to generate an ellipsis, which is +three dots in a row, appropriately spaced @dots{} like so. Do +not simply write three periods in the input file; that would work for +the Info file output, but would produce the wrong amount of space +between the periods in the printed manual. + +Similarly, the @code{@@enddots@{@}} command generates an +end-of-sentence ellipsis, which has different spacing afterwards, +@enddots{} Look closely to see the difference. + +@iftex +Here is an ellipsis: @dots{} +Here are three periods in a row: ... + +In printed output, the three periods in a row are much closer together than +the dots in the ellipsis. +@end iftex + + +@node bullet +@subsection @code{@@bullet}@{@} (@bullet{}) +@findex bullet + +Use the @code{@@bullet@{@}} command to generate a large round dot, or +the closest possible thing to one. In Info, an asterisk is used.@refill + +Here is a bullet: @bullet{} + +When you use @code{@@bullet} in @code{@@itemize}, you do not need to +type the braces, because @code{@@itemize} supplies them. +(@xref{itemize, , @code{@@itemize}}.)@refill + + +@node TeX and copyright +@section Inserting @TeX{} and Legal Symbols: @copyright{}, @registeredsymbol{} + +The logo `@TeX{}' is typeset in a special fashion and it needs an +@@-command. The copyright and registered symbols, `@copyright{}' and +`@registeredsymbol{}', is also special. Each of these commands is +followed by a pair of braces, @samp{@{@}}, without any whitespace +between the name of the command and the braces. + +@menu +* tex:: The @TeX{} logos. +* copyright symbol:: The copyright symbol (c in a circle). +* registered symbol:: The registered symbol (R in a circle). +@end menu + + +@node tex +@subsection @code{@@TeX}@{@} (@TeX{}) and @code{@@LaTeX}@{@} (@LaTeX{}) +@findex TeX +@findex LaTeX +@cindex Logos, @TeX{} +@cindex @TeX{} logo +@cindex @LaTeX{} logo + +Use the @code{@@TeX@{@}} command to generate `@TeX{}'. In a printed +manual, this is a special logo that is different from three ordinary +letters. In Info, it just looks like @samp{TeX}. + +Similarly, use the @code{@@LaTeX@{@}} command to generate `@LaTeX{}', +which is even more special in printed manuals (and different from the +incorrect @code{La@@TeX@{@}}. In Info, the result is just +@samp{LaTeX}. (@LaTeX{} is another macro package built on top of +@TeX{}, very loosely analogous to Texinfo in that it emphasizes +logical structure, but much (much) larger.) + +The spelling of these commands are unusual among Texinfo commands in +that they use both uppercase and lowercase letters. + + +@node copyright symbol +@subsection @code{@@copyright@{@}} (@copyright{}) +@findex copyright +@cindex Copyright symbol + +Use the @code{@@copyright@{@}} command to generate the copyright +symbol, `@copyright{}'. Where possible, this is a @samp{c} +inside a circle; in Info, this is @samp{(C)}. + + +@node registered symbol +@subsection @code{@@registeredsymbol@{@}} (@registeredsymbol{}) +@findex registeredsymbol +@cindex Registered symbol + +Use the @code{@@registeredsymbol@{@}} command to generate the +registered symbol, `@registeredsymbol{}'. Where possible, this is an +@samp{R} inside a circle; in Info, this is @samp{(R)}. + + +@node euro +@section @code{@@euro}@{@} (@euro{}): Euro Currency Symbol +@findex euro +@cindex Euro symbol + +Use the @code{@@euro@{@}} command to generate `@euro{}'. Where +possible, this is the symbol for the Euro currency, invented as part +of the European economic unification. In plain Info, it is the word +@samp{Euro }. A trailing space is included in the text +transliteration since typically no space is desired after the symbol, +so it would be inappropriate to have a space in the source document. + +Texinfo cannot magically synthesize support for the Euro symbol where +the underlying system (fonts, software, whatever) does not support +it. Therefore, in many cases it is preferable to use the word +``Euro''. (In banking circles, the abbreviation for the Euro is EUR.) + +@cindex ISO 8859-15 +@cindex Latin 9 +In order to get the Euro symbol in encoded Info output, for example, +it is necessary to specify @code{@@documentencoding ISO-8859-15}. +(@xref{documentencoding,,@code{@@documentencoding}}.) The Euro symbol +is in ISO 8859-15 (aka Latin@tie{}9), and is @emph{not} in the more +widely-used and supported ISO 8859-1 (Latin@tie{}1). + +@pindex feymr10 +@cindex Euro font +The Euro symbol does not exist in the standard @TeX{} fonts (which +were designed before the Euro was legislated into existence). +Therefore, @TeX{} uses an additional font, named @code{feymr10} (along +with other variables). It is freely available, of course; you can +download it from @url{http://www.ctan.org/tex-archive/fonts/eurosym}, +among other places. The distribution includes installation +instructions. + + +@node pounds +@section @code{@@pounds}@{@} (@pounds{}): Pounds Sterling +@findex pounds +@cindex Pounds symbol + +Use the @code{@@pounds@{@}} command to generate `@pounds{}'. Where +possible, this is the symbol for the currency pounds sterling. In +Info, it is a @samp{#}. + + +@node textdegree +@section @code{@@textdegree}@{@} (@textdegree{}): Degrees Symbol +@findex textdegree +@cindex Degree symbol + +Use the @code{@@textdegree@{@}} command to generate `@textdegree{}'. +Where possible, this is the normal symbol for degrees. In plain text +and Info output, it is an @samp{o}. + + +@node minus +@section @code{@@minus}@{@} (@minus{}): Inserting a Minus Sign +@findex minus +@cindex Minus sign + +@cindex Em dash, compared to minus sign +@cindex Hyphen, compared to minus +Use the @code{@@minus@{@}} command to generate a minus sign. In a +fixed-width font, this is a single hyphen, but in a proportional font, +the symbol is the customary length for a minus sign---a little longer +than a hyphen, shorter than an em-dash: + +@display +@samp{@minus{}} is a minus sign generated with @samp{@@minus@{@}}, + +`-' is a hyphen generated with the character @samp{-}, + +`---' is an em-dash for text. +@end display + +@noindent +In the fixed-width font used by Info, @code{@@minus@{@}} is the same +as a hyphen. + +You should not use @code{@@minus@{@}} inside @code{@@code} or +@code{@@example} because the width distinction is not made in the +fixed-width font they use. + +When you use @code{@@minus} to specify the mark beginning each entry in +an itemized list, you do not need to type the braces +(@pxref{itemize, , @code{@@itemize}}). + + +@node geq leq +@section @code{@@geq@{@}} (@geq{}) and @code{@@leq@{@}} (@leq{}): Inserting relations +@findex geq +@findex leq + +Use the @code{@@geq@{@}} and @code{@@geq@{@}} commands to generate +greater-than-or-equal and less-than-equal-signs, `@geq{}' and +`@leq{}'. In plain text and Info output, these are the ASCII +sequences @samp{>=} and @samp{<=}. The + + +@node math +@section @code{@@math}: Inserting Mathematical Expressions +@findex math +@cindex Mathematical expressions +@cindex Formulas, mathematical + +You can write a short mathematical expression with the @code{@@math} +command. Write the mathematical expression between braces, like this: + +@example +@@math@{(a + b)(a + b) = a^2 + 2ab + b^2@} +@end example + +@iftex +@noindent This produces the following in @TeX{}: + +@display +@math{(a + b)(a + b) = a^2 + 2ab + b^2} +@end display + +@noindent and the following in other formats: +@end iftex +@ifnottex +@noindent This produces the following in Info and HTML: +@end ifnottex + +@example +(a + b)(a + b) = a^2 + 2ab + b^2 +@end example + +The @code{@@math} command has no special effect on the Info and HTML +output. @command{makeinfo} expands any @code{@@}-commands as usual, +but it does not try to produce good mathematical formatting in any +way. + +However, as far as the @TeX{} output is concerned, plain @TeX{} +mathematical commands are allowed in @code{@@math}, starting with +@samp{\}, and the plain @TeX{} math characters like @samp{^} and +@samp{_} are also recognized. In essence, @code{@@math} drops you +into plain @TeX{} math mode. + +This allows you to conveniently write superscripts and subscripts (as +in the above example), and also to use all the plain @TeX{} math +control sequences for symbols, functions, and so on, and thus get +proper formatting in the @TeX{} output, at least. + +It's best to use @samp{\} instead of @samp{@@} for any such +mathematical commands; otherwise, @command{makeinfo} will complain. +On the other hand, input with matching (but unescaped) braces, such as +@samp{k_@{75@}}, is allowed inside @code{@@math}, although +@command{makeinfo} would complain about the bare braces in regular +input. + +Here's an example: + +@example +@@math@{\sin 2\pi \equiv \cos 3\pi@} +@end example + +@iftex +@noindent which looks like this in @TeX{}: +@display +@math{\sin 2\pi \equiv \cos 3\pi} +@end display + +@noindent and +@end iftex +@noindent which looks like the input in Info and HTML: +@example +\sin 2\pi \equiv \cos 3\pi +@end example + +@findex \ @r{(literal \ in @code{@@math})} +Since @samp{\} is an escape character inside @code{@@math}, you can use +@code{@@\} to get a literal backslash (@code{\\} will work in @TeX{}, +but you'd get the literal @samp{\\} in Info). @code{@@\} is not +defined outside of @code{@@math}, since a @samp{\} ordinarily produces a +literal @samp{\}. + +@cindex Displayed equations +@cindex Equations, displayed +For displayed equations, you must at present use @TeX{} directly +(@pxref{Raw Formatter Commands}). + + +@node Click Sequences +@section Click Sequences +@cindex Click sequences +@cindex Sequence of clicks +@cindex GUI click sequence + +@findex clicksequence +When documenting graphical interfaces, it is necessary to describe +sequences such as `Click on @samp{File}, then choose @samp{Open}, then +@dots{}'. Texinfo offers commands @code{@@clicksequence} and +@code{click} to represent this, typically used like this: + +@example +@dots{} @@clicksequence@{File @@click@{@} Open@} @dots{} +@end example + +@noindent +which produces: + +@display +@dots{} @clicksequence{File @click{} Open} @dots{} +@end display + +@findex click +@findex arrow +The @code{@@click} command produces a simple right arrow (@samp{->} in +Info) by default; this glyph is also available independently via the +command @code{@@arrow@{@}}. + +@findex clickstyle +You can change the glyph produced by @code{@@click} with the command +@code{@@clickstyle}, which takes a command name as its single argument +on the rest of the line, much like @code{@@itemize} and friends +(@pxref{itemize,,@code{@@itemize}}). The command should produce a +glyph, and the usual empty braces @samp{@{@}} are omitted. Here's an +example: + +@example +@@clickstyle @@result +@dots{} @@clicksequence@{File @@click@{@} Open@} @dots{} +@end example + +@noindent +now produces: + +@display +@clickstyle @result +@dots{} @clicksequence{File @click{} Open} @dots{} +@end display + + +@node Glyphs +@section Glyphs for Examples +@cindex Glyphs +@cindex Examples, glyphs for + +In Texinfo, code is often illustrated in examples that are delimited +by @code{@@example} and @code{@@end example}, or by @code{@@lisp} and +@code{@@end lisp}. In such examples, you can indicate the results of +evaluation or an expansion using @samp{@result{}} or +@samp{@expansion{}}. Likewise, there are commands to insert glyphs +to indicate +printed output, error messages, equivalence of expressions, and the +location of point. + +The glyph-insertion commands do not need to be used within an example, but +most often they are. Every glyph-insertion command is followed by a pair of +left- and right-hand braces.@refill + +@menu +* Glyphs Summary:: +* result:: How to show the result of expression. +* expansion:: How to indicate an expansion. +* Print Glyph:: How to indicate printed output. +* Error Glyph:: How to indicate an error message. +* Equivalence:: How to indicate equivalence. +* Point Glyph:: How to indicate the location of point. +@end menu + + +@node Glyphs Summary +@subsection Glyphs Summary + +Here are the different glyph commands:@refill + +@table @asis +@item @result{} +@code{@@result@{@}} points to the result of an expression.@refill + +@item @expansion{} +@code{@@expansion@{@}} shows the results of a macro expansion.@refill + +@item @print{} +@code{@@print@{@}} indicates printed output.@refill + +@item @error{} +@code{@@error@{@}} indicates that the following text is an error +message.@refill + +@item @equiv{} +@code{@@equiv@{@}} indicates the exact equivalence of two forms.@refill + +@item @point{} +@code{@@point@{@}} shows the location of point.@refill +@end table + +@menu +* result:: +* expansion:: +* Print Glyph:: +* Error Glyph:: +* Equivalence:: +* Point Glyph:: +@end menu + + +@node result +@subsection @code{@@result@{@}} (@result{}): Indicating Evaluation +@cindex Result of an expression +@cindex Indicating evaluation +@cindex Evaluation glyph +@cindex Value of an expression, indicating +@findex result + +Use the @code{@@result@{@}} command to indicate the result of +evaluating an expression.@refill + +@iftex +The @code{@@result@{@}} command is displayed as @samp{@result{}} in +the printed output and as @samp{=>} in other formats. +@end iftex +@ifnottex +The @code{@@result@{@}} command is displayed as @samp{@result{}} in +Info and HTML and as a true double stemmed arrow in the printed output. +@end ifnottex + +Thus, the following, + +@lisp +(cdr '(1 2 3)) + @result{} (2 3) +@end lisp + +@noindent +may be read as ``@code{(cdr '(1 2 3))} evaluates to @code{(2 3)}''. + + +@node expansion +@subsection @code{@@expansion@{@}} (@expansion{}): Indicating an Expansion +@cindex Expansion, indicating +@cindex Macro expansion, indicating +@findex expansion + +When an expression is a macro call, it expands into a new expression. +You can indicate the result of the expansion with the +@code{@@expansion@{@}} command.@refill + +@iftex +The @code{@@expansion@{@}} command is displayed as @samp{@expansion{}} +in the printed output and as @samp{==>} in other formats. +@end iftex +@ifnottex +The @code{@@expansion@{@}} command is displayed as @samp{@expansion{}} +in Info and HTML, and as a long arrow with a flat base in the printed +output. +@end ifnottex + +@need 700 +For example, the following + +@example +@group +@@lisp +(third '(a b c)) + @@expansion@{@} (car (cdr (cdr '(a b c)))) + @@result@{@} c +@@end lisp +@end group +@end example + +@noindent +produces + +@lisp +@group +(third '(a b c)) + @expansion{} (car (cdr (cdr '(a b c)))) + @result{} c +@end group +@end lisp + +@noindent +which may be read as: + +@quotation +@code{(third '(a b c))} expands to @code{(car (cdr (cdr '(a b c))))}; +the result of evaluating the expression is @code{c}. +@end quotation + +@noindent +Often, as in this case, an example looks better if the +@code{@@expansion@{@}} and @code{@@result@{@}} commands are indented. + + +@node Print Glyph +@subsection @code{@@print@{@}} (@print{}): Indicating Printed Output +@cindex Printed output, indicating +@findex print + +Sometimes an expression will print output during its execution. You +can indicate the printed output with the @code{@@print@{@}} command.@refill + +@iftex +The @code{@@print@{@}} command is displayed as @samp{-|} in Info and +HTML and as @samp{@print{}} in the printed output. +@end iftex +@ifnottex +The @code{@@print@{@}} command is displayed as @samp{@print{}} in Info +and HTML and (similarly) as a horizontal dash butting against a +vertical bar in the printed output. +@end ifnottex + +In the following example, the printed text is indicated with +@samp{@print{}}, and the value of the expression follows on the +last line. + +@lisp +@group +(progn (print 'foo) (print 'bar)) + @print{} foo + @print{} bar + @result{} bar +@end group +@end lisp + +@noindent +In a Texinfo source file, this example is written as follows: + +@lisp +@group +@@lisp +(progn (print 'foo) (print 'bar)) + @@print@{@} foo + @@print@{@} bar + @@result@{@} bar +@@end lisp +@end group +@end lisp + + +@node Error Glyph +@subsection @code{@@error@{@}} (@error{}): Indicating an Error Message +@cindex Error message, indicating +@findex error + +A piece of code may cause an error when you evaluate it. You can +designate the error message with the @code{@@error@{@}} command.@refill + +@iftex +The @code{@@error@{@}} command is displayed as @samp{error-->} in Info +and HTML and as @samp{@error{}} in the printed output. +@end iftex +@ifnottex +The @code{@@error@{@}} command is displayed as @samp{@error{}} in Info +and HTML and as the word `error' in a box in the printed output. +@end ifnottex + +@need 700 +Thus, + +@example +@@lisp +(+ 23 'x) +@@error@{@} Wrong type argument: integer-or-marker-p, x +@@end lisp +@end example + +@noindent +produces + +@lisp +(+ 23 'x) +@error{} Wrong type argument: integer-or-marker-p, x +@end lisp + +@noindent +This indicates that the following error message is printed +when you evaluate the expression: + +@lisp +Wrong type argument: integer-or-marker-p, x +@end lisp + +@samp{@error{}} itself is not part of the error message. + + +@node Equivalence +@subsection @code{@@equiv@{@}} (@equiv{}): Indicating Equivalence +@cindex Equivalence, indicating +@findex equiv + +Sometimes two expressions produce identical results. You can indicate the +exact equivalence of two forms with the @code{@@equiv@{@}} command.@refill + +@iftex +The @code{@@equiv@{@}} command is displayed as @samp{==} in Info and +HTML and as @samp{@equiv{}} in the printed output. +@end iftex +@ifnottex +The @code{@@equiv@{@}} command is displayed as @samp{@equiv{}} in Info +and HTML and as a standard mathematical equivalence sign (three +parallel horizontal lines) in the printed output. +@end ifnottex + +Thus, + +@example +@@lisp +(make-sparse-keymap) @@equiv@{@} (list 'keymap) +@@end lisp +@end example + +@noindent +produces + +@lisp +(make-sparse-keymap) @equiv{} (list 'keymap) +@end lisp + +@noindent +This indicates that evaluating @code{(make-sparse-keymap)} produces +identical results to evaluating @code{(list 'keymap)}. + + +@node Point Glyph +@subsection @code{@@point@{@}} (@point{}): Indicating Point in a Buffer +@cindex Point, indicating in a buffer +@findex point + +Sometimes you need to show an example of text in an Emacs buffer. In +such examples, the convention is to include the entire contents of the +buffer in question between two lines of dashes containing the buffer +name.@refill + +You can use the @samp{@@point@{@}} command to show the location of point +in the text in the buffer. (The symbol for point, of course, is not +part of the text in the buffer; it indicates the place @emph{between} +two characters where point is located.)@refill + +@iftex +The @code{@@point@{@}} command is displayed as @samp{-!-} in Info and +HTML and as @samp{@point{}} in the printed output. +@end iftex +@ifnottex +The @code{@@point@{@}} command is displayed as @samp{@point{}} in Info +and HTML and as a small five pointed star in the printed +output. +@end ifnottex + +The following example shows the contents of buffer @file{foo} before +and after evaluating a Lisp command to insert the word @code{changed}.@refill + +@example +@group +---------- Buffer: foo ---------- +This is the @point{}contents of foo. +---------- Buffer: foo ---------- + +@end group +@end example + +@example +@group +(insert "changed ") + @result{} nil +---------- Buffer: foo ---------- +This is the changed @point{}contents of foo. +---------- Buffer: foo ---------- + +@end group +@end example + +In a Texinfo source file, the example is written like this:@refill + +@example +@@example +---------- Buffer: foo ---------- +This is the @@point@{@}contents of foo. +---------- Buffer: foo ---------- + +(insert "changed ") + @@result@{@} nil +---------- Buffer: foo ---------- +This is the changed @@point@{@}contents of foo. +---------- Buffer: foo ---------- +@@end example +@end example + + +@node Breaks +@chapter Forcing and Preventing Breaks +@cindex Forcing line and page breaks +@cindex Making line and page breaks +@cindex Preventing line and page breaks + +@cindex Line breaks +Usually, a Texinfo file is processed both by @TeX{} and by one of the +Info formatting commands. Line, paragraph, or page breaks sometimes +occur in the `wrong' place in one or other form of output. You must +ensure that text looks right both in the printed manual and in the +Info file. + +@cindex White space, excessive +@cindex Page breaks +For example, in a printed manual, page breaks may occur awkwardly in +the middle of an example; to prevent this, you can hold text together +using a grouping command that keeps the text from being split across +two pages. Conversely, you may want to force a page break where none +would occur normally. Fortunately, problems like these do not often +arise. When they do, use the break, break prevention, or pagination +commands. + +@menu +* Break Commands:: Summary of break-related commands. +* Line Breaks:: Forcing line breaks. +* - and hyphenation:: Helping @TeX{} with hyphenation points. +* allowcodebreaks:: Controlling line breaks within @@code text. +* w:: Preventing unwanted line breaks in text. +* tie:: Inserting an unbreakable but varying space. +* sp:: Inserting blank lines. +* page:: Forcing the start of a new page. +* group:: Preventing unwanted page breaks. +* need:: Another way to prevent unwanted page breaks. +@end menu + + +@node Break Commands +@section Break Commands + +The break commands create or allow line and paragraph breaks: + +@table @code +@item @@* +Force a line break. + +@item @@sp @var{n} +Skip @var{n} blank lines. + +@item @@- +Insert a discretionary hyphen. + +@item @@hyphenation@{@var{hy-phen-a-ted words}@} +Define hyphen points in @var{hy-phen-a-ted words}. +@end table + +These commands hold text together on a single line: + +@table @code +@item @@w@{@var{text}@} +Prevent @var{text} from being split and hyphenated across two lines. +@item @@tie@{@} +Insert a normal interword space at which a line break may not occur. +@end table +@iftex +@sp 1 +@end iftex + +The pagination commands apply only to printed output, since Info +files do not have pages. + +@table @code +@item @@page +Start a new page in the printed manual. + +@item @@group +Hold text together that must appear on one printed page. + +@item @@need @var{mils} +Start a new printed page if not enough space on this one. +@end table + + +@node Line Breaks +@section @code{@@*} and @code{@@/}: Generate and Allow Line Breaks +@findex * @r{(force line break)} +@findex / @r{(allow line break)} +@cindex Line breaks +@cindex Breaks in a line +@cindex Force line break +@cindex Allow line break + +The @code{@@*} command forces a line break in both the printed manual and +in Info. The @code{@@/} command allows a line break (printed manual only). + +Here is an example with @code{@@*}: + +@example +This line @@* is broken @@*in two places. +@end example + +@noindent produces + +@example +@group +This line +is broken +in two places. +@end group +@end example + +The @code{@@/} command can be useful within a url +(@pxref{uref,,@code{@@uref}}), which tend to be long and are otherwise +unbreakable. For example: + +@example +The official Texinfo home page is on the GNU web site: +@@uref@{http://www.gnu.org/@@/software/@@/gnu/@@/texinfo@}. +@end example + +@noindent produces + +@display +The official Texinfo home page is on the GNU web site: +@uref{http://www.gnu.org/@/software/@/gnu/@/texinfo}. +@end display + +@noindent Without the @code{@@/} commands, @TeX{} would have nowhere to +break the line. @code{@@/} has no effect in the online output. + + +@node - and hyphenation +@section @code{@@-} and @code{@@hyphenation}: Helping @TeX{} Hyphenate + +@findex - @r{(discretionary hyphen)} +@findex hyphenation +@cindex Hyphenation, helping @TeX{} do +@cindex Fine-tuning, and hyphenation + +Although @TeX{}'s hyphenation algorithm is generally pretty good, it +does miss useful hyphenation points from time to time. (Or, far more +rarely, insert an incorrect hyphenation.) So, for documents with an +unusual vocabulary or when fine-tuning for a printed edition, you may +wish to help @TeX{} out. Texinfo supports two commands for this: + +@table @code +@item @@- +Insert a discretionary hyphen, i.e., a place where @TeX{} can (but does +not have to) hyphenate. This is especially useful when you notice an +overfull hbox is due to @TeX{} missing a hyphenation (@pxref{Overfull +hboxes}). @TeX{} will not insert any hyphenation points itself into a +word containing @code{@@-}. + +@item @@hyphenation@{@var{hy-phen-a-ted words}@} +Tell @TeX{} how to hyphenate @var{hy-phen-a-ted words}. As shown, you +put a @samp{-} at each hyphenation point. For example: +@example +@@hyphenation@{man-u-script man-u-scripts@} +@end example +@noindent @TeX{} only uses the specified hyphenation points when the +words match exactly, so give all necessary variants, such as plurals. +@end table + +Info, HTML, and other non-@TeX{} output is not hyphenated, so none of +these commands have any effect there. + + +@node allowcodebreaks +@section @code{@@allowcodebreaks}: Control Line Breaks in @code{@@code} + +@findex allowcodebreaks +@cindex Breaks, within @code{@@code} +@cindex -, breakpoint within @code{@@code} +@cindex Hyphen, breakpoint within @code{@@code} +@cindex Dash, breakpoint within @code{@@code} +@cindex _, breakpoint within @code{@@code} +@cindex Underscore, breakpoint within @code{@@code} + +Ordinarily, @TeX{} will consider breaking lines at @samp{-} and +@samp{_} characters within @code{@@code} and related commands +(@pxref{code,,@code{@@code}}), more or less as if they were ``empty'' +hyphenation points. + +This is necessary as many manuals, especially for Lisp-family +languages, must document very long identifiers. On the other hand, +other manuals don't have this problems, and you may not wish to allow +a line break at the underscore in, for example, @code{SIZE_MAX}, or +even worse, after any of the four underscores in @code{__typeof__}. + +So Texinfo provides this command: + +@example +@@allowcodebreaks false +@end example + +@noindent to prevent @TeX{} from breaking at @samp{-} or @samp{_} within +@code{@@code}. You can go back to allowing such breaks with +@code{@@allowcodebreaks true}. Write these commands on lines by +themselves. + +These commands can be given anywhere in the document. For example, +you may have just one problematic paragraph where you need to turn off +the breaks, but want them in general, or vice versa. + +This command has no effect in Info, HTML, and other non-@TeX{} output. + + +@node w +@section @code{@@w}@{@var{text}@}: Prevent Line Breaks +@findex w @r{(prevent line break)} +@cindex Line breaks, preventing + +@code{@@w@{@var{text}@}} outputs @var{text} and prohibits line breaks +within @var{text}, for both @TeX{} and @command{makeinfo}. + +@cindex Non-breakable space, fixed +@cindex Unbreakable space, fixed +Thus, you can use @code{@@w} to produce a non-breakable space, fixed at +the width of a normal interword space: + +@example +@@w@{ @} @@w@{ @} @@w@{ @} indentation. +@end example + +@noindent produces: + +@display +@w{ } @w{ } @w{ } indentation. +@end display + +The space from @code{@@w@{@w{ }@}}, as well as being non-breakable, +also will not stretch or shrink. Sometimes that is what you want, for +instance if you're doing manual indenting. However, usually you want +a normal interword space that does stretch and shrink (in the printed +output); see the @code{@@tie} command in the next section. + +@cindex Hyphenation, preventing +You can also use the @code{@@w} command to prevent @TeX{} from +automatically hyphenating a long name or phrase that happens to fall +near the end of a line. @command{makeinfo} does not ever hyphenate +words. + +@cindex Keyword expansion, preventing +@cindex Version control keywords, preventing expansion of +@cindex $Id expansion, preventing +You can also use @code{@@w} to avoid unwanted keyword expansion in +source control systems. For example, to literally write @t{@w{$}Id$} +in your document, use @code{@@w@{$@}Id$}. + + +@node tie +@section @code{@@tie@{@}}: Inserting an Unbreakable Space +@findex tie @r{(unbreakable interword space)} +@cindex Tied space +@cindex Non-breakable space, variable +@cindex Unbreakable space, variable + +The @code{@@tie@{@}} command produces a normal interword space at which +a line break may not occur. Always write it with following (empty) +braces, as usual for commands used within a paragraph. Here's an +example: + +@example +@@TeX@{@} was written by Donald E.@@tie@{@}Knuth. +@end example + +@noindent produces: + +@display +@TeX{} was written by Donald E.@tie{}Knuth. +@end display + +There are two important differences between @code{@@tie@{@}} and +@code{@@w@{@w{ }@}}: + +@itemize +@item +The space produced by @code{@@tie@{@}} will stretch and shrink slightly +along with the normal interword spaces in the paragraph; the space +produced by @code{@@w@{@w{ }@}} will not vary. + +@item +@code{@@tie@{@}} allows hyphenation of the surrounding words, while +@code{@@w@{@w{ }@}} inhibits hyphenation of those words (for @TeX{}nical +reasons, namely that it produces an @samp{\hbox}). + +@end itemize + + +@node sp +@section @code{@@sp} @var{n}: Insert Blank Lines +@findex sp @r{(line spacing)} +@cindex Space, inserting vertical +@cindex Blank lines +@cindex Line spacing + +A line beginning with and containing only @code{@@sp @var{n}} +generates @var{n} blank lines of space in both the printed manual and +the Info file. @code{@@sp} also forces a paragraph break. For +example, + +@example +@@sp 2 +@end example + +@noindent +generates two blank lines. + +The @code{@@sp} command is most often used in the title page.@refill + +@ignore +@c node br, page, sp, Breaks +@comment node-name, next, previous, up +@c section @code{@@br}: Generate Paragraph Breaks +@findex br @r{(paragraph breaks)} +@cindex Paragraph breaks +@cindex Breaks in a paragraph + +The @code{@@br} command forces a paragraph break. It inserts a blank +line. You can use the command within or at the end of a line. If +used within a line, the @code{@@br@{@}} command must be followed by +left and right braces (as shown here) to mark the end of the +command.@refill + +@need 700 +For example, + +@example +@group +This line @@br@{@}contains and is ended by paragraph breaks@@br +and is followed by another line. +@end group +@end example + +@noindent +produces + +@example +@group +This line + +contains and is ended by paragraph breaks + +and is followed by another line. +@end group +@end example + +The @code{@@br} command is seldom used. +@end ignore + + +@node page +@section @code{@@page}: Start a New Page +@cindex Page breaks +@findex page + +A line containing only @code{@@page} starts a new page in a printed +manual. The command has no effect on Info files since they are not +paginated. An @code{@@page} command is often used in the @code{@@titlepage} +section of a Texinfo file to start the copyright page. + + +@node group +@comment node-name, next, previous, up +@section @code{@@group}: Prevent Page Breaks +@cindex Group (hold text together vertically) +@cindex Holding text together vertically +@cindex Vertically holding text together +@findex group + +The @code{@@group} command (on a line by itself) is used inside an +@code{@@example} or similar construct to begin an unsplittable vertical +group, which will appear entirely on one page in the printed output. +The group is terminated by a line containing only @code{@@end group}. +These two lines produce no output of their own, and in the Info file +output they have no effect at all.@refill + +@c Once said that these environments +@c turn off vertical spacing between ``paragraphs''. +@c Also, quotation used to work, but doesn't in texinfo-2.72 +Although @code{@@group} would make sense conceptually in a wide +variety of contexts, its current implementation works reliably only +within @code{@@example} and variants, and within @code{@@display}, +@code{@@format}, @code{@@flushleft} and @code{@@flushright}. +@xref{Quotations and Examples}. (What all these commands have in +common is that each line of input produces a line of output.) In +other contexts, @code{@@group} can cause anomalous vertical +spacing.@refill + +@need 750 +This formatting requirement means that you should write: + +@example +@group +@@example +@@group +@dots{} +@@end group +@@end example +@end group +@end example + +@noindent +with the @code{@@group} and @code{@@end group} commands inside the +@code{@@example} and @code{@@end example} commands. + +The @code{@@group} command is most often used to hold an example +together on one page. In this Texinfo manual, more than 100 examples +contain text that is enclosed between @code{@@group} and @code{@@end +group}. + +If you forget to end a group, you may get strange and unfathomable +error messages when you run @TeX{}. This is because @TeX{} keeps +trying to put the rest of the Texinfo file onto the one page and does +not start to generate error messages until it has processed +considerable text. It is a good rule of thumb to look for a missing +@code{@@end group} if you get incomprehensible error messages in +@TeX{}.@refill + +@node need +@comment node-name, next, previous, up +@section @code{@@need @var{mils}}: Prevent Page Breaks +@cindex Need space at page bottom +@findex need + +A line containing only @code{@@need @var{n}} starts +a new page in a printed manual if fewer than @var{n} mils (thousandths +of an inch) remain on the current page. Do not use +braces around the argument @var{n}. The @code{@@need} command has no +effect on Info files since they are not paginated.@refill + +@need 800 +This paragraph is preceded by an @code{@@need} command that tells +@TeX{} to start a new page if fewer than 800 mils (eight-tenths +inch) remain on the page. It looks like this:@refill + +@example +@group +@@need 800 +This paragraph is preceded by @dots{} +@end group +@end example + +The @code{@@need} command is useful for preventing orphans (single +lines at the bottoms of printed pages).@refill + + +@node Definition Commands +@chapter Definition Commands +@cindex Definition commands + +The @code{@@deffn} command and the other @dfn{definition commands} +enable you to describe functions, variables, macros, commands, user +options, special forms and other such artifacts in a uniform +format.@refill + +In the Info file, a definition causes the entity +category---`Function', `Variable', or whatever---to appear at the +beginning of the first line of the definition, followed by the +entity's name and arguments. In the printed manual, the command +causes @TeX{} to print the entity's name and its arguments on the left +margin and print the category next to the right margin. In both +output formats, the body of the definition is indented. Also, the +name of the entity is entered into the appropriate index: +@code{@@deffn} enters the name into the index of functions, +@code{@@defvr} enters it into the index of variables, and so +on (@pxref{Predefined Indices}). + +A manual need not and should not contain more than one definition for +a given name. An appendix containing a summary should use +@code{@@table} rather than the definition commands.@refill + +@menu +* Def Cmd Template:: Writing descriptions using definition commands. +* Def Cmd Continuation Lines:: Continuing the heading over source lines. +* Optional Arguments:: Handling optional and repeated arguments. +* deffnx:: Group two or more `first' lines. +* Def Cmds in Detail:: Reference for all the definition commands. +* Def Cmd Conventions:: Conventions for writing definitions. +* Sample Function Definition:: An example. +@end menu + + +@node Def Cmd Template +@section The Template for a Definition +@cindex Definition template +@cindex Template for a definition + +The @code{@@deffn} command is used for definitions of entities that +resemble functions. To write a definition using the @code{@@deffn} +command, write the @code{@@deffn} command at the beginning of a line +and follow it on the same line by the category of the entity, the name +of the entity itself, and its arguments (if any). Then write the body +of the definition on succeeding lines. (You may embed examples in the +body.) Finally, end the definition with an @code{@@end deffn} command +written on a line of its own. + +The other definition commands follow the same format: a line with the +@code{@@def@dots{}} command and whatever arguments are appropriate for +that command; the body of the definition; and a corresponding +@code{@@end} line. + +The template for a definition looks like this: + +@example +@group +@@deffn @var{category} @var{name} @var{arguments}@dots{} +@var{body-of-definition} +@@end deffn +@end group +@end example + +@need 700 +@noindent +For example, + +@example +@group +@@deffn Command forward-word count +This command moves point forward @@var@{count@} words +(or backward if @@var@{count@} is negative). @dots{} +@@end deffn +@end group +@end example + +@noindent +produces + +@quotation +@deffn Command forward-word count +This command moves point forward @var{count} words +(or backward if @var{count} is negative). @dots{} +@end deffn +@end quotation + +Capitalize the category name like a title. If the name of the +category contains spaces, as in the phrase `Interactive Command', +enclose it in braces. For example: + +@example +@group +@@deffn @{Interactive Command@} isearch-forward +@dots{} +@@end deffn +@end group +@end example + +@noindent +Otherwise, the second word will be mistaken for the name of the +entity. As a general rule, when any of the arguments in the heading +line @emph{except} the last one are more than one word, you need to +enclose them in braces. This may also be necessary if the text +contains commands, for example, @samp{@{declaraci@@'on@}} if you are +writing in Spanish. + +Some of the definition commands are more general than others. The +@code{@@deffn} command, for example, is the general definition command +for functions and the like---for entities that may take arguments. +When you use this command, you specify the category to which the +entity belongs. Three predefined, specialized variations +(@code{@@defun}, @code{@@defmac}, and @code{@@defspec}) specify the +category for you: ``Function'', ``Macro'', and ``Special Form'' +respectively. (In Lisp, a special form is an entity much like a +function.) Similarly, the general @code{@@defvr} command is +accompanied by several specialized variations for describing +particular kinds of variables. + +@xref{Sample Function Definition}, for a detailed example of a +function definition, including the use of @code{@@example} inside the +definition. + +@cindex Macros in definition commands +Unfortunately, due to implementation difficulties, macros are not expanded +in @code{@@deffn} and all the other definition commands. + + +@node Def Cmd Continuation Lines +@section Definition Command Continuation Lines +@cindex Continuation lines in definition commands +@cindex Definition command headings, continuing +@cindex @samp{@@} as continuation in definition commands + +The heading line of a definition command can get very long. +Therefore, Texinfo has a special syntax allowing them to be continued +over multiple lines of the source file: a lone @samp{@@} at the end of +each line to be continued. Here's an example: + +@example +@@defun fn-name @@ + arg1 arg2 arg3 +This is the basic continued defun. +@@end defun +@end example + +@noindent produces: + +@defun fn-name @ + arg1 arg2 arg3 +This is the basic continued defun. +@end defun + +@noindent +As you can see, the continued lines are combined, as if they had been +typed on one source line. + +Although this example only shows a one-line continuation, +continuations may extend over any number of lines; simply put an +@code{@@} at the end of each line to be continued. + +The @code{@@} character does not have to be the last character on the +physical line: whitespace is allowed (and ignored) afterwards. + +@cindex Whitespace, collapsed around continuations +@cindex Collapsing whitespace around continuations +In general, any number of spaces or tabs around the @code{@@} +continuation character, both on the line with the @code{@@} and on the +continued line, are collapsed into a single space. There is one +exception: the Texinfo processors will not fully collapse whitespace +around a continuation inside braces. For example: + +@example +@@deffn @{Category @@ + Name@} @dots{} +@end example + +@noindent The output (not shown) has excess space between `Category' +and `Name'. In this case, simply elide any unwanted whitespace in +your input, or put the continuation @code{@@} outside braces. + +@code{@@} does not (currently) function as a continuation character in +@emph{any} other context. Ordinarily, @samp{@@} followed by a +whitespace character (space, tab, newline) produces a normal interword +space (@pxref{Multiple Spaces}). + + +@node Optional Arguments +@section Optional and Repeated Arguments +@cindex Optional and repeated arguments +@cindex Repeated and optional arguments +@cindex Arguments, repeated and optional +@cindex Syntax, optional & repeated arguments +@cindex Meta-syntactic chars for arguments + +Some entities take optional or repeated arguments, which may be +specified by a distinctive glyph that uses square brackets and +ellipses. For @w{example}, a special form often breaks its argument list +into separate arguments in more complicated ways than a +straightforward function. + +@c This is consistent with Emacs Lisp Reference manual +An argument enclosed within square brackets is optional. +Thus, [@var{optional-arg}] means that @var{optional-arg} is optional. +An argument followed by an ellipsis is optional +and may be repeated more than once. +@c This is consistent with Emacs Lisp Reference manual +Thus, @var{repeated-args}@samp{@dots{}} stands for zero or more +arguments. Parentheses are used when several arguments are grouped +into additional levels of list structure in Lisp. + +Here is the @code{@@defspec} line of an example of an imaginary +special form: + +@quotation +@defspec foobar (@var{var} [@var{from} @var{to} [@var{inc}]]) @var{body}@dots{} +@end defspec +@tex +\vskip \parskip +@end tex +@end quotation + +@noindent +In this example, the arguments @var{from} and @var{to} are optional, +but must both be present or both absent. If they are present, +@var{inc} may optionally be specified as well. These arguments are +grouped with the argument @var{var} into a list, to distinguish them +from @var{body}, which includes all remaining elements of the +form.@refill + +In a Texinfo source file, this @code{@@defspec} line is written like +this (except it would not be split over two lines, as it is in this +example).@refill + +@example +@group +@@defspec foobar (@@var@{var@} [@@var@{from@} @@var@{to@} + [@@var@{inc@}]]) @@var@{body@}@@dots@{@} +@end group +@end example + +@noindent +The function is listed in the Command and Variable Index under +@samp{foobar}.@refill + + +@node deffnx +@section Two or More `First' Lines +@cindex Two `First' Lines for @code{@@deffn} +@cindex Grouping two definitions together +@cindex Definitions grouped together +@findex deffnx + +To create two or more `first' or header lines for a definition, follow +the first @code{@@deffn} line by a line beginning with @code{@@deffnx}. +The @code{@@deffnx} command works exactly like @code{@@deffn} +except that it does not generate extra vertical white space between it +and the preceding line.@refill + +@need 1000 +For example, + +@example +@group +@@deffn @{Interactive Command@} isearch-forward +@@deffnx @{Interactive Command@} isearch-backward +These two search commands are similar except @dots{} +@@end deffn +@end group +@end example + +@noindent +produces + +@deffn {Interactive Command} isearch-forward +@deffnx {Interactive Command} isearch-backward +These two search commands are similar except @dots{} +@end deffn + +Each definition command has an `x' form: @code{@@defunx}, +@code{@@defvrx}, @code{@@deftypefunx}, etc. + +The `x' forms work similarly to @code{@@itemx} (@pxref{itemx}). + + +@node Def Cmds in Detail +@section The Definition Commands + +Texinfo provides more than a dozen definition commands, all of which +are described in this section.@refill + +The definition commands automatically enter the name of the entity in +the appropriate index: for example, @code{@@deffn}, @code{@@defun}, +and @code{@@defmac} enter function names in the index of functions; +@code{@@defvr} and @code{@@defvar} enter variable names in the index +of variables.@refill + +Although the examples that follow mostly illustrate Lisp, the commands +can be used for other programming languages.@refill + +@menu +* Functions Commands:: Commands for functions and similar entities. +* Variables Commands:: Commands for variables and similar entities. +* Typed Functions:: Commands for functions in typed languages. +* Typed Variables:: Commands for variables in typed languages. +* Data Types:: The definition command for data types. +* Abstract Objects:: Commands for object-oriented programming. +@end menu + +@node Functions Commands +@subsection Functions and Similar Entities + +This section describes the commands for describing functions and similar +entities:@refill + +@table @code +@findex deffn +@item @@deffn @var{category} @var{name} @var{arguments}@dots{} +The @code{@@deffn} command is the general definition command for +functions, interactive commands, and similar entities that may take +arguments. You must choose a term to describe the category of entity +being defined; for example, ``Function'' could be used if the entity is +a function. The @code{@@deffn} command is written at the beginning of a +line and is followed on the same line by the category of entity being +described, the name of this particular entity, and its arguments, if +any. Terminate the definition with @code{@@end deffn} on a line of its +own.@refill + +@need 750 +For example, here is a definition: + +@example +@group +@@deffn Command forward-char nchars +Move point forward @@var@{nchars@} characters. +@@end deffn +@end group +@end example + +@noindent +This shows a rather terse definition for a ``command'' named +@code{forward-char} with one argument, @var{nchars}. + +@code{@@deffn} and prints argument names such as @var{nchars} in slanted +type in the printed output, because we think of these names as +metasyntactic variables---they stand for the actual argument values. +Within the text of the description, however, write an argument name +explicitly with @code{@@var} to refer to the value of the argument. +In the example above, we used @samp{@@var@{nchars@}} in this way. + +In the unusual case when an argument name contains @samp{--}, or +another character sequence which is treated specially +(@pxref{Conventions}), use @code{@@var} around the argument. This +causes the name to be printed in slanted typewriter, instead of the +regular slanted font, exactly as input. +@c except for ?` and !`, but we won't explain that. + +The template for @code{@@deffn} is: + +@example +@group +@@deffn @var{category} @var{name} @var{arguments}@dots{} +@var{body-of-definition} +@@end deffn +@end group +@end example + +@findex defun +@item @@defun @var{name} @var{arguments}@dots{} +The @code{@@defun} command is the definition command for functions. +@code{@@defun} is equivalent to @samp{@@deffn Function @dots{}}. +Terminate the definition with @code{@@end defun} on a line of its own. +Thus, the template is: + +@example +@group +@@defun @var{function-name} @var{arguments}@dots{} +@var{body-of-definition} +@@end defun +@end group +@end example + +@findex defmac +@item @@defmac @var{name} @var{arguments}@dots{} +The @code{@@defmac} command is the definition command for macros. +@code{@@defmac} is equivalent to @samp{@@deffn Macro @dots{}} and +works like @code{@@defun}. + +@findex defspec +@item @@defspec @var{name} @var{arguments}@dots{} +The @code{@@defspec} command is the definition command for special +forms. (In Lisp, a special form is an entity much like a function, +@pxref{Special Forms,,, elisp, GNU Emacs Lisp Reference Manual}.) +@code{@@defspec} is equivalent to @samp{@@deffn @{Special Form@} +@dots{}} and works like @code{@@defun}. +@end table + +All these commands create entries in the index of functions. + + +@node Variables Commands +@subsection Variables and Similar Entities + +Here are the commands for defining variables and similar +entities:@refill + +@table @code +@findex defvr +@item @@defvr @var{category} @var{name} +The @code{@@defvr} command is a general definition command for +something like a variable---an entity that records a value. You must +choose a term to describe the category of entity being defined; for +example, ``Variable'' could be used if the entity is a variable. +Write the @code{@@defvr} command at the beginning of a line and +follow it on the same line by the category of the entity and the +name of the entity. + +Capitalize the category name like a title. If the name of the category +contains spaces, as in the name ``User Option'', enclose it in braces. +Otherwise, the second word will be mistaken for the name of the entity. +For example, + +@example +@group +@@defvr @{User Option@} fill-column +This buffer-local variable specifies +the maximum width of filled lines. +@dots{} +@@end defvr +@end group +@end example + +Terminate the definition with @code{@@end defvr} on a line of its +own.@refill + +The template is: + +@example +@group +@@defvr @var{category} @var{name} +@var{body-of-definition} +@@end defvr +@end group +@end example + +@code{@@defvr} creates an entry in the index of variables for @var{name}. + +@findex defvar +@item @@defvar @var{name} +The @code{@@defvar} command is the definition command for variables. +@code{@@defvar} is equivalent to @samp{@@defvr Variable +@dots{}}.@refill + +@need 750 +For example: + +@example +@group +@@defvar kill-ring +@dots{} +@@end defvar +@end group +@end example + +The template is: + +@example +@group +@@defvar @var{name} +@var{body-of-definition} +@@end defvar +@end group +@end example + +@code{@@defvar} creates an entry in the index of variables for +@var{name}.@refill + +@findex defopt +@item @@defopt @var{name} +@cindex User options, marking +The @code{@@defopt} command is the definition command for @dfn{user +options}, i.e., variables intended for users to change according to +taste; Emacs has many such (@pxref{Variables,,, emacs, The GNU Emacs +Manual}). @code{@@defopt} is equivalent to @samp{@@defvr @{User +Option@} @dots{}} and works like @code{@@defvar}. It creates an entry +in the index of variables. +@end table + + +@node Typed Functions +@subsection Functions in Typed Languages + +The @code{@@deftypefn} command and its variations are for describing +functions in languages in which you must declare types of variables and +functions, such as C and C++. + +@table @code +@findex deftypefn +@item @@deftypefn @var{category} @var{data-type} @var{name} @var{arguments}@dots{} +The @code{@@deftypefn} command is the general definition command for +functions and similar entities that may take arguments and that are +typed. The @code{@@deftypefn} command is written at the beginning of +a line and is followed on the same line by the category of entity +being described, the type of the returned value, the name of this +particular entity, and its arguments, if any.@refill + +@need 800 +@noindent +For example, + +@example +@group +@@deftypefn @{Library Function@} int foobar + (int @@var@{foo@}, float @@var@{bar@}) +@dots{} +@@end deftypefn +@end group +@end example + +@need 1000 +@noindent +(where the text before the ``@dots{}'', shown above as two lines, would +actually be a single line in a real Texinfo file) produces the following +in Info: + +@smallexample +@group +-- Library Function: int foobar (int FOO, float BAR) +@dots{} +@end group +@end smallexample +@iftex + +In a printed manual, it produces: + +@quotation +@deftypefn {Library Function} int foobar (int @var{foo}, float @var{bar}) +@dots{} +@end deftypefn +@end quotation +@end iftex + +This means that @code{foobar} is a ``library function'' that returns an +@code{int}, and its arguments are @var{foo} (an @code{int}) and +@var{bar} (a @code{float}).@refill + +Since in typed languages, the actual names of the arguments are +typically scattered among data type names and keywords, Texinfo cannot +find them without help. You can either (a)@tie{}write everything +as straight text, and it will be printed in slanted type; (b)@tie{}use +@code{@@var} for the variable names, which will uppercase the +variable names in Info and use the slanted typewriter font in printed +output; (c)@tie{}use @code{@@var} for the variable names and +@code{@@code} for the type names and keywords, which will be dutifully +obeyed. + +The template for @code{@@deftypefn} is:@refill + +@example +@group +@@deftypefn @var{category} @var{data-type} @var{name} @var{arguments} @dots{} +@var{body-of-description} +@@end deftypefn +@end group +@end example + +@noindent +Note that if the @var{category} or @var{data type} is more than one +word then it must be enclosed in braces to make it a single argument.@refill + +If you are describing a procedure in a language that has packages, +such as Ada, you might consider using @code{@@deftypefn} in a manner +somewhat contrary to the convention described in the preceding +paragraphs. For example: + +@example +@group +@@deftypefn stacks private push @@ + (@@var@{s@}:in out stack; @@ + @@var@{n@}:in integer) +@dots{} +@@end deftypefn +@end group +@end example + +@noindent +(The @code{@@deftypefn} arguments are shown using continuations +(@pxref{Def Cmd Continuation Lines}), but could be on a single line in +a real Texinfo file.) + +In this instance, the procedure is classified as belonging to the +package @code{stacks} rather than classified as a `procedure' and its +data type is described as @code{private}. (The name of the procedure +is @code{push}, and its arguments are @var{s} and @var{n}.)@refill + +@code{@@deftypefn} creates an entry in the index of functions for +@var{name}. + +@item @@deftypefun @var{data-type} @var{name} @var{arguments}@dots{} +@findex deftypefun +The @code{@@deftypefun} command is the specialized definition command +for functions in typed languages. The command is equivalent to +@samp{@@deftypefn Function @dots{}}. The template is: + +@example +@group +@@deftypefun @var{type} @var{name} @var{arguments}@dots{} +@var{body-of-description} +@@end deftypefun +@end group +@end example + +@code{@@deftypefun} creates an entry in the index of functions for +@var{name}. + +@end table + + +@node Typed Variables +@subsection Variables in Typed Languages + +Variables in typed languages are handled in a manner similar to +functions in typed languages. @xref{Typed Functions}. The general +definition command @code{@@deftypevr} corresponds to +@code{@@deftypefn} and the specialized definition command +@code{@@deftypevar} corresponds to @code{@@deftypefun}.@refill + +@table @code +@findex deftypevr +@item @@deftypevr @var{category} @var{data-type} @var{name} +The @code{@@deftypevr} command is the general definition command for +something like a variable in a typed language---an entity that records +a value. You must choose a term to describe the category of the +entity being defined; for example, ``Variable'' could be used if the +entity is a variable.@refill + +The @code{@@deftypevr} command is written at the beginning of a line +and is followed on the same line by the category of the entity +being described, the data type, and the name of this particular +entity.@refill + +@need 800 +@noindent +For example: + +@example +@group +@@deftypevr @{Global Flag@} int enable +@dots{} +@@end deftypevr +@end group +@end example + +@noindent +produces the following in Info: + +@example +@group +-- Global Flag: int enable +@dots{} +@end group +@end example +@iftex + +@noindent +and the following in a printed manual: + +@quotation +@deftypevr {Global Flag} int enable +@dots{} +@end deftypevr +@end quotation +@end iftex + +@need 800 +The template is: + +@example +@@deftypevr @var{category} @var{data-type} @var{name} +@var{body-of-description} +@@end deftypevr +@end example + +@findex deftypevar +@item @@deftypevar @var{data-type} @var{name} +The @code{@@deftypevar} command is the specialized definition command +for variables in typed languages. @code{@@deftypevar} is equivalent +to @samp{@@deftypevr Variable @dots{}}. The template is: + +@example +@group +@@deftypevar @var{data-type} @var{name} +@var{body-of-description} +@@end deftypevar +@end group +@end example +@end table + +These commands create entries in the index of variables. + +@node Data Types +@subsection Data Types + +Here is the command for data types:@refill + +@table @code +@findex deftp +@item @@deftp @var{category} @var{name} @var{attributes}@dots{} +The @code{@@deftp} command is the generic definition command for data +types. The command is written at the beginning of a line and is +followed on the same line by the category, by the name of the type +(which is a word like @code{int} or @code{float}), and then by names of +attributes of objects of that type. Thus, you could use this command +for describing @code{int} or @code{float}, in which case you could use +@code{data type} as the category. (A data type is a category of +certain objects for purposes of deciding which operations can be +performed on them.)@refill + +In Lisp, for example, @dfn{pair} names a particular data +type, and an object of that type has two slots called the +@sc{car} and the @sc{cdr}. Here is how you would write the first line +of a definition of @code{pair}.@refill + +@example +@group +@@deftp @{Data type@} pair car cdr +@dots{} +@@end deftp +@end group +@end example + +@need 950 +The template is: + +@example +@group +@@deftp @var{category} @var{name-of-type} @var{attributes}@dots{} +@var{body-of-definition} +@@end deftp +@end group +@end example + +@code{@@deftp} creates an entry in the index of data types. +@end table + + +@node Abstract Objects +@subsection Object-Oriented Programming + +@cindex Object-oriented programming + +Here are the commands for formatting descriptions about abstract +objects, such as are used in object-oriented programming. A class is +a defined type of abstract object. An instance of a class is a +particular object that has the type of the class. An instance +variable is a variable that belongs to the class but for which each +instance has its own value. + +@menu +* Variables: Object-Oriented Variables. +* Methods: Object-Oriented Methods. +@end menu + + +@node Object-Oriented Variables +@subsubsection Object-Oriented Variables + +@cindex Variables, object-oriented + +These commands allow you to define different sorts of variables in +object-oriented programming languages. + +@table @code +@item @@defcv @var{category} @var{class} @var{name} +@findex defcv +The @code{@@defcv} command is the general definition command for +variables associated with classes in object-oriented programming. The +@code{@@defcv} command is followed by three arguments: the category of +thing being defined, the class to which it belongs, and its +name. For instance: + +@example +@group +@@defcv @{Class Option@} Window border-pattern +@dots{} +@@end defcv +@end group +@end example + +@noindent produces: +@defcv {Class Option} Window border-pattern +@dots{} +@end defcv + +@code{@@defcv} creates an entry in the index of variables. + +@item @@deftypecv @var{category} @var{class} @var{data-type} @var{name} +@findex deftypecv +The @code{@@deftypecv} command is the definition command for typed +class variables in object-oriented programming. It is analogous to +@code{@@defcv} with the addition of the @var{data-type} parameter to +specify the type of the instance variable. Ordinarily, the data type +is a programming language construct that should be marked with +@code{@@code}. For instance: + +@example +@group +@@deftypecv @{Class Option@} Window @@code@{int@} border-pattern +@dots{} +@@end deftypecv +@end group +@end example + +@noindent produces: + +@deftypecv {Class Option} Window @code{int} border-pattern +@dots{} +@end deftypecv + +@code{@@deftypecv} creates an entry in the index of variables. + +@item @@defivar @var{class} @var{name} +@findex defivar +The @code{@@defivar} command is the definition command for instance +variables in object-oriented programming. @code{@@defivar} is +equivalent to @samp{@@defcv @{Instance Variable@} @dots{}}. For +instance: + +@example +@group +@@defivar Window border-pattern +@dots{} +@@end defivar +@end group +@end example + +@noindent produces: + +@defivar Window border-pattern +@dots{} +@end defivar + +@code{@@defivar} creates an entry in the index of variables. + +@item @@deftypeivar @var{class} @var{data-type} @var{name} +@findex deftypeivar +The @code{@@deftypeivar} command is the definition command for typed +instance variables in object-oriented programming. It is analogous to +@code{@@defivar} with the addition of the @var{data-type} parameter to +specify the type of the instance variable. Ordinarily, the data type +is a programming language construct that should be marked with +@code{@@code}. For instance: + +@example +@group +@@deftypeivar Window @@code@{int@} border-pattern +@dots{} +@@end deftypeivar +@end group +@end example + +@noindent produces: + +@deftypeivar Window @code{int} border-pattern +@dots{} +@end deftypeivar + +@code{@@deftypeivar} creates an entry in the index of variables. + +@end table + +@node Object-Oriented Methods +@subsubsection Object-Oriented Methods + +@cindex Methods, object-oriented + +These commands allow you to define different sorts of function-like +entities resembling methods in object-oriented programming languages. +These entities take arguments, as functions do, but are associated with +particular classes of objects. + +@table @code + +@findex defop +@item @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{} +The @code{@@defop} command is the general definition command for these +method-like entities. + +For example, some systems have constructs called @dfn{wrappers} that +are associated with classes as methods are, but that act more like +macros than like functions. You could use @code{@@defop Wrapper} to +describe one of these.@refill + +Sometimes it is useful to distinguish methods and @dfn{operations}. +You can think of an operation as the specification for a method. +Thus, a window system might specify that all window classes have a +method named @code{expose}; we would say that this window system +defines an @code{expose} operation on windows in general. Typically, +the operation has a name and also specifies the pattern of arguments; +all methods that implement the operation must accept the same +arguments, since applications that use the operation do so without +knowing which method will implement it.@refill + +Often it makes more sense to document operations than methods. For +example, window application developers need to know about the +@code{expose} operation, but need not be concerned with whether a +given class of windows has its own method to implement this operation. +To describe this operation, you would write:@refill + +@example +@@defop Operation windows expose +@end example + +The @code{@@defop} command is written at the beginning of a line and +is followed on the same line by the overall name of the category of +operation, the name of the class of the operation, the name of the +operation, and its arguments, if any.@refill + +The template is: +@example +@group +@@defop @var{category} @var{class} @var{name} @var{arguments}@dots{} +@var{body-of-definition} +@@end defop +@end group +@end example + +@code{@@defop} creates an entry, such as `@code{expose} on +@code{windows}', in the index of functions.@refill + +@findex deftypeop +@item @@deftypeop @var{category} @var{class} @var{data-type} @var{name} @var{arguments}@dots{} +The @code{@@deftypeop} command is the definition command for typed +operations in object-oriented programming. It is similar to +@code{@@defop} with the addition of the @var{data-type} parameter to +specify the return type of the method. @code{@@deftypeop} creates an +entry in the index of functions. + +@item @@defmethod @var{class} @var{name} @var{arguments}@dots{} +@findex defmethod +The @code{@@defmethod} command is the definition command for methods +in object-oriented programming. A method is a kind of function that +implements an operation for a particular class of objects and its +subclasses. +@ignore +@c ADR: Who cares?!? +@c KB: Oh, I don't know, I think this info is crucial! +In the Lisp Machine, methods actually were functions, but +they were usually defined with @code{defmethod}. +@end ignore + +@code{@@defmethod} is equivalent to @samp{@@defop Method @dots{}}. +The command is written at the beginning of a line and is followed by +the name of the class of the method, the name of the method, and its +arguments, if any.@refill + +@noindent +For example: +@example +@group +@@defmethod @code{bar-class} bar-method argument +@dots{} +@@end defmethod +@end group +@end example + +@noindent +illustrates the definition for a method called @code{bar-method} of +the class @code{bar-class}. The method takes an argument. + +@code{@@defmethod} creates an entry in the index of functions. + +@item @@deftypemethod @var{class} @var{data-type} @var{name} @var{arguments}@dots{} +@findex defmethod +The @code{@@deftypemethod} command is the definition command for methods +in object-oriented typed languages, such as C++ and Java. It is similar +to the @code{@@defmethod} command with the addition of the +@var{data-type} parameter to specify the return type of the method. +@code{@@deftypemethod} creates an entry in the index of functions. + +@end table + + +@node Def Cmd Conventions +@section Conventions for Writing Definitions +@cindex Definition conventions +@cindex Conventions for writing definitions + +When you write a definition using @code{@@deffn}, @code{@@defun}, or +one of the other definition commands, please take care to use +arguments that indicate the meaning, as with the @var{count} argument +to the @code{forward-word} function. Also, if the name of an argument +contains the name of a type, such as @var{integer}, take care that the +argument actually is of that type.@refill + + +@node Sample Function Definition +@section A Sample Function Definition +@cindex Function definitions +@cindex Command definitions +@cindex Macro definitions +@cindex Sample function definition + +A function definition uses the @code{@@defun} and @code{@@end defun} +commands. The name of the function follows immediately after the +@code{@@defun} command and it is followed, on the same line, by the +parameter list.@refill + +Here is a definition from @ref{Calling Functions,,, elisp, The GNU Emacs +Lisp Reference Manual}. + +@quotation +@defun apply function &rest arguments +@code{apply} calls @var{function} with @var{arguments}, just +like @code{funcall} but with one difference: the last of +@var{arguments} is a list of arguments to give to +@var{function}, rather than a single argument. We also say +that this list is @dfn{appended} to the other arguments. + +@code{apply} returns the result of calling @var{function}. +As with @code{funcall}, @var{function} must either be a Lisp +function or a primitive function; special forms and macros +do not make sense in @code{apply}. + +@example +(setq f 'list) + @result{} list +(apply f 'x 'y 'z) +@error{} Wrong type argument: listp, z +(apply '+ 1 2 '(3 4)) + @result{} 10 +(apply '+ '(1 2 3 4)) + @result{} 10 + +(apply 'append '((a b c) nil (x y z) nil)) + @result{} (a b c x y z) +@end example + +An interesting example of using @code{apply} is found in the description +of @code{mapcar}.@refill +@end defun +@end quotation + +@need 1200 +In the Texinfo source file, this example looks like this: + +@example +@group +@@defun apply function &rest arguments +@@code@{apply@} calls @@var@{function@} with +@@var@{arguments@}, just like @@code@{funcall@} but with one +difference: the last of @@var@{arguments@} is a list of +arguments to give to @@var@{function@}, rather than a single +argument. We also say that this list is @@dfn@{appended@} +to the other arguments. +@end group + +@group +@@code@{apply@} returns the result of calling +@@var@{function@}. As with @@code@{funcall@}, +@@var@{function@} must either be a Lisp function or a +primitive function; special forms and macros do not make +sense in @@code@{apply@}. +@end group + +@group +@@example +(setq f 'list) + @@result@{@} list +(apply f 'x 'y 'z) +@@error@{@} Wrong type argument: listp, z +(apply '+ 1 2 '(3 4)) + @@result@{@} 10 +(apply '+ '(1 2 3 4)) + @@result@{@} 10 + +(apply 'append '((a b c) nil (x y z) nil)) + @@result@{@} (a b c x y z) +@@end example +@end group + +@group +An interesting example of using @@code@{apply@} is found +in the description of @@code@{mapcar@}. +@@end defun +@end group +@end example + +@noindent +In this manual, this function is listed in the Command and Variable +Index under @code{apply}.@refill + +Ordinary variables and user options are described using a format like +that for functions except that variables do not take arguments. + + +@node Conditionals +@chapter Conditionally Visible Text +@cindex Conditionally visible text +@cindex Text, conditionally visible +@cindex Visibility of conditional text +@cindex If text conditionally visible + +The @dfn{conditional commands} allow you to use different text for +different output formats, or for general conditions that you define. +For example, you can use them to specify different text for the +printed manual and the Info output. + +The conditional commands comprise the following categories. + +@itemize @bullet +@item +Commands specific to an output format (Info, @TeX{}, HTML, @dots{}). + +@item +Commands specific to any output format @emph{other} than a given +one (not Info, not @TeX{}, @dots{}). + +@item +`Raw' formatter text for any output format, passed straight +through with no interpretation of @@-commands. + +@item +Format-independent variable substitutions, and testing if a variable +is set or clear. + +@end itemize + +@menu +* Conditional Commands:: Text for a given format. +* Conditional Not Commands:: Text for any format other than a given one. +* Raw Formatter Commands:: Using raw formatter commands. +* set clear value:: Variable tests and substitutions. +* Conditional Nesting:: Using conditionals inside conditionals. +@end menu + + +@node Conditional Commands +@section Conditional Commands + +Texinfo has an @code{@@if@var{format}} environment for each output +format, to allow conditional inclusion of text for a particular output +format. + +@findex ifinfo +@code{@@ifinfo} begins segments of text that should be ignored by +@TeX{} when it typesets the printed manual, and by @command{makeinfo} +when not producing Info output. The segment of text appears only in +the Info file and, for historical compatibility, the plain text +output. + +@findex ifdocbook +@findex ifhtml +@findex ifplaintext +@findex iftex +@findex ifxml +The environments for the other formats are analogous: + +@table @code +@item @@ifdocbook @dots{} @@end ifdocbook +Text to appear only in the Docbook output. + +@item @@ifhtml @dots{} @@end ifhtml +Text to appear only in the HTML output. + +@item @@ifplaintext @dots{} @@end ifplaintext +Text to appear only in the plain text output. + +@item @@iftex @dots{} @@end iftex +Text to appear only in the printed manual. + +@item @@ifxml @dots{} @@end ifxml +Text to appear only in the XML output. +@end table + +The @code{@@if@dots{}} and @code{@@end if@dots{}} commands must appear +on lines by themselves in your source file. + +Here is an example showing all these conditionals: + +@example +@@iftex +This text will appear only in the printed manual. +@@end iftex +@@ifinfo +However, this text will appear only in Info and plain text. +@@end ifinfo +@@ifhtml +And this text will only appear in HTML. +@@end ifhtml +@@ifplaintext +Whereas this text will only appear in plain text. +@@end ifplaintext +@@ifxml +Notwithstanding that this will only appear in XML. +@@end ifxml +@@ifdocbook +Nevertheless, this will only appear in Docbook. +@@end ifdocbook +@end example + +@noindent +The preceding example produces the following line: + +@iftex +This text will appear only in the printed manual. +@end iftex +@ifinfo +However, this text will appear only in Info and plain text. +@end ifinfo +@ifhtml +And this text will only appear in HTML. +@end ifhtml +@ifplaintext +Whereas this text will only appear in plain text. +@end ifplaintext +@ifxml +Notwithstanding that this will only appear in XML. +@end ifxml +@ifdocbook +Nevertheless, this will only appear in Docbook. +@end ifdocbook + +@noindent +Notice that you only see one of the input lines, depending on which +version of the manual you are reading. + + +@node Conditional Not Commands +@section Conditional Not Commands +@findex ifnotdocbook +@findex ifnothtml +@findex ifnotinfo +@findex ifnotplaintext +@findex ifnottex +@findex ifnotxml + +You can specify text to be included in any output format @emph{other} +than a given one with the @code{@@ifnot@dots{}} environments: + +@example +@@ifnotdocbook @dots{} @@end ifnotdocbook +@@ifnothtml @dots{} @@end ifnothtml +@@ifnotinfo @dots{} @@end ifnotinfo +@@ifnotplaintext @dots{} @@end ifnotplaintext +@@ifnottex @dots{} @@end ifnottex +@@ifnotxml @dots{} @@end ifnotxml +@end example + +@noindent +The @code{@@ifnot@dots{}} command and the @code{@@end} command must +appear on lines by themselves in your actual source file. + +If the output file is being made in the given format, the +region is @emph{ignored}. Otherwise, it is included. + +There is one exception (for historical compatibility): +@code{@@ifnotinfo} text is omitted for both Info and plain text +output, not just Info. To specify text which appears only in Info and +not in plain text, use @code{@@ifnotplaintext}, like this: + +@example +@@ifinfo +@@ifnotplaintext +This will be in Info, but not plain text. +@@end ifnotplaintext +@@end ifinfo +@end example + +The regions delimited by these commands are ordinary Texinfo source as +with @code{@@iftex}, not raw formatter source as with @code{@@tex} +(@pxref{Raw Formatter Commands}). + + +@node Raw Formatter Commands +@section Raw Formatter Commands +@cindex Raw formatter commands +@cindex @TeX{} commands, using ordinary +@cindex Ordinary @TeX{} commands, using +@cindex Commands using raw @TeX{} +@cindex Docbook, including raw +@cindex HTML, including raw +@cindex XML, including raw +@cindex Plain @TeX{} + +Inside a region delineated by @code{@@iftex} and @code{@@end iftex}, +you can embed some raw @TeX{} commands. The Texinfo processors will +ignore such a region unless @TeX{} output is being produced. You can +write the @TeX{} commands as you would write them in a normal @TeX{} +file, except that you must replace the @samp{\} used by @TeX{} with an +@samp{@@}. For example, in the @code{@@titlepage} section of a +Texinfo file, you can use the @TeX{} command @code{@@vskip} to format +the copyright page. (The @code{@@titlepage} command causes Info to +ignore the region automatically, as it does with the @code{@@iftex} +command.) + +However, most features of plain @TeX{} will not work within +@code{@@iftex}, as they are overridden by Texinfo features. The +purpose of @code{@@iftex} is to provide conditional processing for the +Texinfo source, not provide access to underlying formatting features. + +@findex tex +You can enter plain @TeX{} completely, and use @samp{\} in the @TeX{} +commands, by delineating a region with the @code{@@tex} and @code{@@end +tex} commands. All plain @TeX{} commands and category codes are +restored within an @code{@@tex} region. The sole exception is that the +@code{@@} character still introduces a command, so that @code{@@end tex} +can be recognized properly. As with @code{@@iftex}, Texinfo +processors will ignore such a region unless @TeX{} output is being produced. + +@findex \gdef @r{within @code{@@tex}} +In complex cases, you may wish to define new @TeX{} macros within +@code{@@tex}. You must use @code{\gdef} to do this, not @code{\def}, +because @code{@@tex} regions are processed in a @TeX{} group. + +@cindex Mathematical expressions +As an example, here is a mathematical expression written in plain @TeX{}: + +@example +@@tex +$$ \chi^2 = \sum_@{i=1@}^N + \left (y_i - (a + b x_i) + \over \sigma_i\right)^2 $$ +@@end tex +@end example + +@noindent +The output of this example will appear only in a printed manual. If +you are reading this in Info, you will not see the equation that appears +in the printed manual. +@iftex +In a printed manual, the above expression looks like +this: +@end iftex + +@tex +$$ \chi^2 = \sum_{i=1}^N + \left(y_i - (a + b x_i) + \over \sigma_i\right)^2 $$ +@end tex + +@findex ifhtml +@findex html +Analogously, you can use @code{@@ifhtml @dots{} @@end ifhtml} to delimit +a region to be included in HTML output only, and @code{@@html @dots{} +@@end html} for a region of raw HTML. + +@findex ifxml +@findex xml +Likewise, you can use @code{@@ifxml @dots{} @@end ifxml} to delimit +a region to be included in XML output only, and @code{@@xml @dots{} +@@end xml} for a region of raw XML. + +@findex ifdocbook +@findex docbook +Again likewise, you can use @code{@@ifdocbook @dots{} @@end ifdocbook} +to delimit a region to be included in Docbook output only, and +@code{@@docbook @dots{} @@end docbook} for a region of raw Docbook. + +In all cases, the exception to the raw processing is that @code{@@} is +still an escape character, so the @code{@@end} command can be +recognized. + + +@node set clear value +@section @code{@@set}, @code{@@clear}, and @code{@@value} + +You can direct the Texinfo formatting commands to format or ignore parts +of a Texinfo file with the @code{@@set}, @code{@@clear}, @code{@@ifset}, +and @code{@@ifclear} commands. + +Here are brief descriptions of these commands, see the following +sections for more details: + +@table @code +@item @@set @var{flag} [@var{value}] +Set the variable @var{flag}, to the optional @var{value} if specified. + +@item @@clear @var{flag} +Undefine the variable @var{flag}, whether or not it was previously defined. + +@item @@ifset @var{flag} +If @var{flag} is set, text through the next @code{@@end ifset} command +is formatted. If @var{flag} is clear, text through the following +@code{@@end ifset} command is ignored. + +@item @@ifclear @var{flag} +If @var{flag} is set, text through the next @code{@@end ifclear} command +is ignored. If @var{flag} is clear, text through the following +@code{@@end ifclear} command is formatted. +@end table + +@menu +* set value:: Expand a flag variable to a string. +* ifset ifclear:: Format a region if a flag is set. +* value Example:: An easy way to update edition information. +@end menu + + +@node set value +@subsection @code{@@set} and @code{@@value} +@findex set +@findex value +@findex clear + +You use the @code{@@set} command to specify a value for a flag, which +is later expanded by the @code{@@value} command. + +A @dfn{flag} (aka @dfn{variable}) is an identifier. It is best to use +only letters and numerals in a flag name, not @samp{-} or +@samp{_}---they will work in some contexts, but not all, due to +limitations in @TeX{}. + +The value is the remainder of the input line, and can contain anything. + +Write the @code{@@set} command like this: + +@example +@@set foo This is a string. +@end example + +@noindent +This sets the value of the flag @code{foo} to ``This is a string.''. + +The Texinfo formatters then replace an @code{@@value@{@var{flag}@}} +command with the string to which @var{flag} is set. Thus, when +@code{foo} is set as shown above, the Texinfo formatters convert this: + +@example +@group +@@value@{foo@} +@exdent @r{to this:} +This is a string. +@end group +@end example + +You can write an @code{@@value} command within a paragraph; but you +must write an @code{@@set} command on a line of its own. + +If you write the @code{@@set} command like this: + +@example +@@set foo +@end example + +@noindent +without specifying a string, the value of @code{foo} is the empty string. + +If you clear a previously set flag with @code{@@clear @var{flag}}, a +subsequent @code{@@value@{flag@}} command will report an error. + +For example, if you set @code{foo} as follows: + +@example +@@set howmuch very, very, very +@end example + +@noindent +then the formatters transform + +@example +@group +It is a @@value@{howmuch@} wet day. +@exdent @r{into} +It is a very, very, very wet day. +@end group +@end example + +If you write + +@example +@@clear howmuch +@end example + +@noindent +then the formatters transform + +@example +@group +It is a @@value@{howmuch@} wet day. +@exdent @r{into} +It is a @{No value for "howmuch"@} wet day. +@end group +@end example + + +@node ifset ifclear +@subsection @code{@@ifset} and @code{@@ifclear} + +@findex ifset +When a @var{flag} is set, the Texinfo formatting commands format text +between subsequent pairs of @code{@@ifset @var{flag}} and @code{@@end +ifset} commands. When the @var{flag} is cleared, the Texinfo formatting +commands do @emph{not} format the text. @code{@@ifclear} operates +analogously. + +Write the conditionally formatted text between @code{@@ifset @var{flag}} +and @code{@@end ifset} commands, like this: + +@example +@group +@@ifset @var{flag} +@var{conditional-text} +@@end ifset +@end group +@end example + +For example, you can create one document that has two variants, such as +a manual for a `large' and `small' model: + +@cindex Shrubbery +@example +You can use this machine to dig up shrubs +without hurting them. + +@@set large + +@@ifset large +It can also dig up fully grown trees. +@@end ifset + +Remember to replant promptly @dots{} +@end example + +@noindent +In the example, the formatting commands will format the text between +@code{@@ifset large} and @code{@@end ifset} because the @code{large} +flag is set. + +When @var{flag} is cleared, the Texinfo formatting commands do +@emph{not} format the text between @code{@@ifset @var{flag}} and +@code{@@end ifset}; that text is ignored and does not appear in either +printed or Info output. + +For example, if you clear the flag of the preceding example by writing +an @code{@@clear large} command after the @code{@@set large} command +(but before the conditional text), then the Texinfo formatting commands +ignore the text between the @code{@@ifset large} and @code{@@end ifset} +commands. In the formatted output, that text does not appear; in both +printed and Info output, you see only the lines that say, ``You can use +this machine to dig up shrubs without hurting them. Remember to replant +promptly @dots{}''. + +@findex ifclear +If a flag is cleared with an @code{@@clear @var{flag}} command, then +the formatting commands format text between subsequent pairs of +@code{@@ifclear} and @code{@@end ifclear} commands. But if the flag +is set with @code{@@set @var{flag}}, then the formatting commands do +@emph{not} format text between an @code{@@ifclear} and an @code{@@end +ifclear} command; rather, they ignore that text. An @code{@@ifclear} +command looks like this: + +@example +@@ifclear @var{flag} +@end example + + +@node value Example +@subsection @code{@@value} Example + +You can use the @code{@@value} command to minimize the number of +places you need to change when you record an update to a manual. +@xref{GNU Sample Texts}, for the full text of an example of using this +to work with Automake distributions. + +This example is adapted from @ref{Top,, Overview, make, The GNU Make +Manual}. + +@enumerate +@item +Set the flags: + +@example +@group +@@set EDITION 0.35 Beta +@@set VERSION 3.63 Beta +@@set UPDATED 14 August 1992 +@@set UPDATE-MONTH August 1992 +@end group +@end example + +@item +Write text for the @code{@@copying} section (@pxref{copying}): + +@example +@group +@@copying +This is Edition @@value@{EDITION@}, +last updated @@value@{UPDATED@}, +of @@cite@{The GNU Make Manual@}, +for @@code@{make@}, version @@value@{VERSION@}. + +Copyright @dots{} + +Permission is granted @dots{} +@@end copying +@end group +@end example + +@item +Write text for the title page, for people reading the printed manual: + +@example +@group +@@titlepage +@@title GNU Make +@@subtitle A Program for Directing Recompilation +@@subtitle Edition @@value@{EDITION@}, @dots{} +@@subtitle @@value@{UPDATE-MONTH@} +@@page +@@insertcopying +@dots{} +@@end titlepage +@end group +@end example + +@noindent +(On a printed cover, a date listing the month and the year looks less +fussy than a date listing the day as well as the month and year.) + +@item +Write text for the Top node, for people reading the Info file: + +@example +@group +@@ifnottex +@@node Top +@@top Make + +@@insertcopying +@dots{} +@@end ifnottex +@end group +@end example + +After you format the manual, the @code{@@value} constructs have been +expanded, so the output contains text like this: + +@example +@group +This is Edition 0.35 Beta, last updated 14 August 1992, +of `The GNU Make Manual', for `make', Version 3.63 Beta. +@end group +@end example +@end enumerate + +When you update the manual, you change only the values of the flags; you +do not need to edit the three sections. + + +@node Conditional Nesting +@section Conditional Nesting +@cindex Conditionals, nested +@cindex Nesting conditionals + +Conditionals can be nested; however, the details are a little tricky. +The difficulty comes with failing conditionals, such as +@code{@@ifhtml} when HTML is not being produced, where the included +text is to be ignored. However, it is not to be @emph{completely} +ignored, since it is useful to have one @code{@@ifset} inside another, +for example---that is a way to include text only if two conditions are +met. Here's an example: + +@example +@@ifset somevar +@@ifset anothervar +Both somevar and anothervar are set. +@@end ifset +@@ifclear anothervar +Somevar is set, anothervar is not. +@@end ifclear +@@end ifset +@end example + +Technically, Texinfo requires that for a failing conditional, the +ignored text must be properly nested with respect to that failing +conditional. Unfortunately, it's not always feasible to check that +@emph{all} conditionals are properly nested, because then the +processors could have to fully interpret the ignored text, which +defeats the purpose of the command. Here's an example illustrating +these rules: + +@example +@@ifset a +@@ifset b +@@ifclear ok - ok, ignored +@@end junky - ok, ignored +@@end ifset +@@c WRONG - missing @@end ifset. +@end example + +Finally, as mentioned above, all conditional commands must be on lines +by themselves, with no text (even spaces) before or after. Otherwise, +the processors cannot reliably determine which commands to consider +for nesting purposes. + + +@node Internationalization +@chapter Internationalization + +@cindex Internationalization +Texinfo has some support for writing in languages other than English, +although this area still needs considerable work. + +For a list of the various accented and special characters Texinfo +supports, see @ref{Inserting Accents}. + +@menu +* documentlanguage:: Declaring the current language. +* documentencoding:: Declaring the input encoding. +@end menu + + +@node documentlanguage +@section @code{@@documentlanguage @var{ll}[_@var{cc}]}: Set the Document Language + +@findex documentlanguage +@cindex Language, declaring +@cindex Locale, declaring +@cindex Document language, declaring + +The @code{@@documentlanguage} command declares the current document +locale. Write it on a line by itself, near the beginning of the +file, but after @code{@@setfilename} +(@pxref{setfilename,,@code{@@setfilename}}): + +@example +@@documentlanguage @var{ll}[_@var{cc}] +@end example + +Include a two-letter ISO@tie{}639-2 language code (@var{ll}) following +the command name, optionally followed by an underscore and two-letter +ISO@tie{}3166 two-letter country code (@var{cc}). If you have a +multilingual document, the intent is to be able to use this command +multiple times, to declare each language change. If the command is +not used at all, the default is @code{en_US} for US English. + +As with GNU Gettext (@pxref{Top,,,gettext, Gettext}), if the country +code is omitted, the main dialect is assumed where possible. For +example, @code{de} is equivalent to @code{de_DE} (German as spoken in +Germany). + +@cindex Document strings, translation of +For Info and other online output, this command changes the translation +of various @dfn{document strings} such as ``see'' in cross-references +(@pxref{Cross References}), ``Function' in defuns (@pxref{Definition +Commands}), and so on. Some strings, such as ``Node:'', ``Next:'', +``Menu:'', etc., are keywords in Info output, so are not translated +there; they are translated in other output formats. + +@cindex @file{txi-@var{cc}.tex} +For @TeX{}, this command causes a file @file{txi-@var{locale}.tex} to +be read (if it exists). If @code{@@setdocumentlanguage} argument +contains the optional @samp{_@var{cc}} suffix, this is tried first. +For example, with @code{@@setdocumentlanguage de_DE}, @TeX{} first +looks for @file{txi-de_DE.tex}, then @file{txi-de.tex}. + +Such a @file{txi-*} file is intended to redefine the various English +words used in @TeX{} output, such as `Chapter', `See', and so on. We +are aware that individual words like these cannot always be translated +in isolation, and that a very different strategy would be required for +ideographic (among other) scripts. Help in improving Texinfo's +language support is welcome. + +@cindex Hyphenation patterns, language-dependent +It would also be desirable for this command to also change @TeX{}'s +ideas of the current hyphenation patterns (via the @TeX{} primitive +@code{\language}), but this is unfortunately not currently +implemented. + +In September 2006, the W3C Internationalization Activity released a +new recommendation for specifying languages: +@url{http://www.rfc-editor.org/rfc/bcp/bcp47.txt}. When Gettext +supports this new scheme, Texinfo will too. + +@cindex ISO 639-2 language codes +@cindex ISO 3166 country codes +@cindex Language codes +@cindex Country codes +Since the lists of language codes and country codes are updated +relatively frequently, we don't attempt to list them here. The valid +language codes are on the official home page for ISO@tie{}639, +@url{http://www.loc.gov/standards/iso639-2/}. The country codes and +the official web site for ISO@tie{}3166 can be found via +@url{http://en.wikipedia.org/wiki/ISO_3166}. + + +@node documentencoding +@section @code{@@documentencoding @var{enc}}: Set Input Encoding + +@findex documentencoding +@cindex Encoding, declaring +@cindex Input encoding, declaring +@cindex Character set, declaring +@cindex Document input encoding + +The @code{@@documentencoding} command declares the input document +encoding. Write it on a line by itself, with a valid encoding +specification following, near the beginning of the file but after +@code{@@setfilename} (@pxref{setfilename,,@code{@@setfilename}}): + +@example +@@documentencoding @var{enc} +@end example + +At present, Texinfo supports only these encodings: + +@table @code +@item US-ASCII +This has no particular effect, but it's included for completeness. + +@itemx UTF-8 +The vast global character encoding, expressed in 8-bit bytes. +The Texinfo processors have no deep knowledge of Unicode; for the most +part, they just pass along the input they are given to the output. + +@itemx ISO-8859-1 +@itemx ISO-8859-15 +@item ISO-8859-2 +These specify the standard encodings for Western European (the first +two) and Eastern European languages (the third), respectively. ISO +8859-15 replaces some little-used characters from 8859-1 (e.g., +precomposed fractions) with more commonly needed ones, such as the +Euro symbol (@euro{}). + +A full description of the encodings is beyond our scope here; +one useful reference is @uref{http://czyborra.com/charsets/iso8859.html}. + +@item koi8-r +This is the commonly used encoding for the Russian language. + +@item koi8-u +This is the commonly used encoding for the Ukrainian language. + +@end table + +Specifying an encoding @var{enc} has the following effects: + +@opindex --enable-encoding +@cindex Local Variables: section, for encoding +@cindex Info output, and encoding +In Info output, unless the option @option{--disable-encoding} is given +to @command{makeinfo}, a so-called `Local Variables' section +(@pxref{File Variables,,,emacs,The GNU Emacs Manual}) is output +including @var{enc}. This allows Info readers to set the encoding +appropriately. + +@example +Local Variables: +coding: @var{enc} +End: +@end example + +Also, in Info and plain text output (barring +@option{--disable-encoding}), accent constructs and special +characters, such as @code{@@'e}, are output as the actual 8-bit +character in the given encoding. + +@cindex HTML output, and encodings +@cindex @code{http-equiv}, and charset specification +@cindex @code{<meta>} HTML tag, and charset specification +In HTML output, a @samp{<meta>} tag is output, in the @samp{<head>} +section of the HTML, that specifies @var{enc}. Web servers and +browsers cooperate to use this information so the correct encoding is +used to display the page, if supported by the system. + +@example +<meta http-equiv="Content-Type" content="text/html; + charset=@var{enc}"> +@end example + +In split HTML output, if @option{--transliterate-file-names} is +given (@pxref{HTML Xref 8-bit Character Expansion}), the names of HTML +files are formed by transliteration of the corresponding node names, +using the specified encoding. + +In XML and Docbook output, the given document encoding is written in +the output file as usual with those formats. + +In @TeX{} output, the characters which are supported in the standard +Computer Modern fonts are output accordingly. (For example, this +means using constructed accents rather than precomposed glyphs.) +Using a missing character generates a warning message, as does +specifying an unimplemented encoding. + + +@node Defining New Texinfo Commands +@chapter Defining New Texinfo Commands +@cindex Macros +@cindex Defining new Texinfo commands +@cindex New Texinfo commands, defining +@cindex Texinfo commands, defining new +@cindex User-defined Texinfo commands + +Texinfo provides several ways to define new commands: + +@itemize @bullet +@item +A Texinfo @dfn{macro} allows you to define a new Texinfo command as any +sequence of text and/or existing commands (including other macros). The +macro can have any number of @dfn{parameters}---text you supply each +time you use the macro. + +Incidentally, these macros have nothing to do with the @code{@@defmac} +command, which is for documenting macros in the subject of the manual +(@pxref{Def Cmd Template}). + +@item +@samp{@@alias} is a convenient way to define a new name for an existing +command. + +@item +@samp{@@definfoenclose} allows you to define new commands with +customized output in the Info file. + +@end itemize + +@menu +* Defining Macros:: Defining and undefining new commands. +* Invoking Macros:: Using a macro, once you've defined it. +* Macro Details:: Limitations of Texinfo macros. +* alias:: Command aliases. +* definfoenclose:: Customized highlighting. +@end menu + + +@node Defining Macros +@section Defining Macros +@cindex Defining macros +@cindex Macro definitions + +@findex macro +You use the Texinfo @code{@@macro} command to define a macro, like this: + +@example +@@macro @var{macroname}@{@var{param1}, @var{param2}, @dots{}@} +@var{text} @dots{} \@var{param1}\ @dots{} +@@end macro +@end example + +The @dfn{parameters} @var{param1}, @var{param2}, @dots{} correspond to +arguments supplied when the macro is subsequently used in the document +(described in the next section). + +@cindex Macro names, valid characters in +@cindex Names of macros, valid characters of +For a macro to work consistently with @TeX{}, @var{macroname} must +consist entirely of letters: no digits, hyphens, underscores, or other +special characters. So, we recommend using only letters. However, +@command{makeinfo} will accept anything except @samp{@{@}_^=}; +@samp{_} and @samp{^} are excluded so that macros can be called in +@code{@@math} mode without a following space +(@pxref{math,,@code{@@math}}). + +If a macro needs no parameters, you can define it either with an empty +list (@samp{@@macro foo @{@}}) or with no braces at all (@samp{@@macro +foo}). + +@cindex Body of a macro +@cindex Mutually recursive macros +@cindex Recursion, mutual +The definition or @dfn{body} of the macro can contain most Texinfo +commands, including previously-defined macros. Not-yet-defined macro +invocations are not allowed; thus, it is not possible to have mutually +recursive Texinfo macros. Also, a macro definition that defines another +macro does not work in @TeX{} due to limitations in the design of +@code{@@macro}. + +@cindex Parameters to macros +In the macro body, instances of a parameter name surrounded by +backslashes, as in @samp{\@var{param1}\} in the example above, are +replaced by the corresponding argument from the macro invocation. You +can use parameter names any number of times in the body, including zero. + +@cindex Backslash in macros +To get a single @samp{\} in the macro expansion, use @samp{\\}. Any +other use of @samp{\} in the body yields a warning. + +@cindex Spaces in macros +@cindex Whitespace in macros +The newlines after the @code{@@macro} line and before the @code{@@end +macro} line are ignored, that is, not included in the macro body. All +other whitespace is treated according to the usual Texinfo rules. + +@cindex Recursive macro invocations +@findex rmacro +To allow a macro to be used recursively, that is, in an argument to a +call to itself, you must define it with @samp{@@rmacro}, like this: + +@example +@@rmacro rmac @{arg@} +a\arg\b +@@end rmacro +@dots{} +@@rmac@{1@@rmac@{text@}2@} +@end example + +This produces the output `a1atextb2b'. With @samp{@@macro} instead of +@samp{@@rmacro}, an error message is given. + +@findex unmacro +@cindex Macros, undefining +@cindex Undefining macros +You can undefine a macro @var{foo} with @code{@@unmacro @var{foo}}. +It is not an error to undefine a macro that is already undefined. +For example: + +@example +@@unmacro foo +@end example + + +@node Invoking Macros +@section Invoking Macros +@cindex Invoking macros +@cindex Expanding macros +@cindex Running macros +@cindex Macro invocation + +After a macro is defined (see the previous section), you can use +(@dfn{invoke}) it in your document like this: + +@example +@@@var{macroname} @{@var{arg1}, @var{arg2}, @dots{}@} +@end example + +@noindent and the result will be just as if you typed the body of +@var{macroname} at that spot. For example: + +@example +@@macro foo @{p, q@} +Together: \p\ & \q\. +@@end macro +@@foo@{a, b@} +@end example + +@noindent produces: + +@display +Together: a & b. +@end display + +@cindex Backslash, and macros +Thus, the arguments and parameters are separated by commas and delimited +by braces; any whitespace after (but not before) a comma is ignored. +The braces are required in the invocation (but not the definition), even +when the macro takes no arguments, consistent with all other Texinfo +commands. For example: + +@example +@@macro argless @{@} +No arguments here. +@@end macro +@@argless@{@} +@end example + +@noindent produces: + +@display +No arguments here. +@end display + +@cindex Comma, in macro arguments +Passing strings containing commas as macro arguments requires special +care, since they should be properly @dfn{quoted} to prevent +@command{makeinfo} from confusing them with argument separators. To +manually quote a comma, prepend it with a backslash character, like +this: @code{\,}. Alternatively, use the @code{@@comma} command +(@pxref{Inserting a Comma}). However, to facilitate use of macros, +@command{makeinfo} implements a set of rules called @dfn{automatic +quoting}: + +@enumerate 1 +@item If a macro takes only one argument, all commas in its invocation +are quoted by default. For example: + +@example +@group +@@macro FIXME@{text@} +@@strong@{FIXME: \text\@} +@@end macro + +@@FIXME@{A nice feature, though it can be dangerous.@} +@end group +@end example + +@noindent +will produce the following output + +@example +@strong{FIXME: A nice feature, though it can be dangerous.} +@end example + +And indeed, it can. Namely, @command{makeinfo} +does not control number of arguments passed to one-argument +macros, so be careful when you invoke them. + +@item If a macro invocation includes another command (including a +recursive invocation of itself), any commas in the nested command +invocation(s) are quoted by default. For example, in + +@example +@@say@{@@strong@{Yes, I do@}, person one@} +@end example + +the comma after @samp{Yes} is implicitly quoted. Here's another +example, with a recursive macro: + +@example +@group +@@rmacro cat@{a,b@} +\a\\b\ +@@end rmacro + +@@cat@{@@cat@{foo, bar@}, baz@} +@end group +@end example + +@noindent +will produce the string @samp{foobarbaz}. + +@item Otherwise, a comma should be explicitly quoted, as above, to be +treated as a part of an argument. +@end enumerate + +@cindex Braces, in macro arguments +Other characters that need to be quoted in macro arguments are +curly braces and backslash. For example + +@example +@@@var{macname} @{\\\@{\@}\,@} +@end example + +@noindent +will pass the (almost certainly error-producing) argument +@samp{\@{@},} to @var{macname}. However, commas in parameters, even +if escaped by a backslash, might cause trouble in @TeX{}. + +If the macro is defined to take a single argument, and is invoked +without any braces, the entire rest of the line after the macro name is +supplied as the argument. For example: + +@example +@@macro bar @{p@} +Twice: \p\ & \p\. +@@end macro +@@bar aah +@end example + +@noindent produces: + +@c Sorry for cheating, but let's not require macros to process the manual. +@display +Twice: aah & aah. +@end display + +If the macro is defined to take a single argument, and is invoked with +braces, the braced text is passed as the argument, regardless of +commas. For example: + +@example +@@macro bar @{p@} +Twice: \p\ & \p\. +@@end macro +@@bar@{a,b@} +@end example + +@noindent produces: + +@display +Twice: a,b & a,b. +@end display + + +@node Macro Details +@section Macro Details and Caveats +@cindex Macro details +@cindex Details of macro usage +@cindex Caveats for macro usage + +Due to unavoidable limitations, certain macro-related constructs cause +problems with @TeX{}. If you get macro-related errors when producing +the printed version of a manual, try expanding the macros with +@command{makeinfo} by invoking @command{texi2dvi} with the @samp{-E} +option (@pxref{Format with texi2dvi}). + +@itemize @bullet +@item +As mentioned earlier, macro names must consist entirely of letters. + +@item +It is not advisable to redefine any @TeX{} primitive, plain, or +Texinfo command name as a macro. Unfortunately this is a very large +set of names, and the possible resulting errors are unpredictable. + +@item +All macros are expanded inside at least one @TeX{} group. This means +that @code{@@set} and other such commands have no effect inside a +macro. + +@item +Commas in macro arguments, even if escaped by a backslash, don't +always work. + +@item +Macro arguments cannot cross lines. + +@item +It is (usually) best to avoid comments inside macro definitions, but +see the next item. + +@item +Macros containing a command which must be on a line by itself, such as +a conditional, cannot be invoked in the middle of a line. In general, +the interaction of newlines in the macro definitions and invocations +depends on the precise commands and context. You may be able to work +around some problems with judicious use of @code{@@c}. Suppose you +define a macro that is always intended to be used on a line by itself: + +@example +@@macro linemac +@@cindex whatever +@@c +@@end macro +... +foo +@@linemac +bar +@end example + +Without the @code{@@c}, there will be an unwanted blank line between +the @samp{@@cindex whatever} and the @samp{bar} (one newline comes +from the macro definition, one from after the invocation), causing a +paragraph break. + +On the other hand, you wouldn't want the @code{@@c} if the macro was +sometimes invoked in the middle of a line (the text after the +invocation would be treated as a comment). + +@item +In general, you can't arbitrarily substitute a macro call for Texinfo +command arguments, even when the text is the same. It might work with +some commands, it fails with others. Best not to do it at all. For +instance, this fails: + +@example +@@macro offmacro +off +@@end macro +@@headings @@offmacro +@end example + +@noindent +You would expect this to be equivalent to @code{@@headings off}, but +for @TeX{}nical reasons, it fails with a mysterious error message +(@code{Paragraph ended before @@headings was complete}). + +@item +Macros cannot define macros in the natural way. To do this, you must +use conditionals and raw @TeX{}. For example: + +@example +@@ifnottex +@@macro ctor @{name, arg@} +@@macro \name\ +something involving \arg\ somehow +@@end macro +@@end macro +@@end ifnottex +@@tex +\gdef\ctor#1@{\ctorx#1,@} +\gdef\ctorx#1,#2,@{\def#1@{something involving #2 somehow@}@} +@@end tex +@end example + +@end itemize + +The @command{makeinfo} implementation also has limitations: + +@itemize +@item +@code{@@verbatim} and macros do not mix; for instance, you can't start +a verbatim block inside a macro and end it outside. +(@xref{verbatim}.) Starting any environment inside a macro and ending +it outside may or may not work, for that matter. + +@item +Macros that completely define macros are ok, but it's not possible to +have incorrectly nested macro definitions. That is, @code{@@macro} +and @code{@@end macro} (likewise for @code{@@rmacro}) must be +correctly paired. For example, you cannot start a macro definition +within a macro, and then end the nested definition outside the macro. + +@item +@code{@@rmacro} is a kludge. + +@end itemize + +One more limitation is common to both implementations: white space is +ignored at the beginnings of lines. + +Future major revisions of Texinfo may ease some of these limitations +(by introducing a new macro syntax). + + +@node alias +@section @samp{@@alias @var{new}=@var{existing}} +@cindex Aliases, command +@cindex Command aliases +@findex alias + +The @samp{@@alias} command defines a new command to be just like an +existing one. This is useful for defining additional markup names, thus +preserving semantic information in the input even though the output +result may be the same. + +Write the @samp{@@alias} command on a line by itself, followed by the +new command name, an equals sign, and the existing command name. +Whitespace around the equals sign is ignored. Thus: +@example +@@alias @var{new} = @var{existing} +@end example + +For example, if your document contains citations for both books and +some other media (movies, for example), you might like to define a +macro @code{@@moviecite@{@}} that does the same thing as an ordinary +@code{@@cite@{@}} but conveys the extra semantic information as well. +You'd do this as follows: + +@example +@@alias moviecite = cite +@end example + +Macros do not always have the same effect as aliases, due to vagaries +of argument parsing. Also, aliases are much simpler to define than +macros. So the command is not redundant. (It was also heavily used +in the Jargon File!) + +Aliases must not be recursive, directly or indirectly. + +It is not advisable to redefine any @TeX{} primitive, plain, or +Texinfo command name as an alias. Unfortunately this is a very large +set of names, and the possible resulting errors are completely random. + + +@node definfoenclose +@section @samp{definfoenclose}: Customized Highlighting +@cindex Highlighting, customized +@cindex Customized highlighting +@findex definfoenclose + +A @code{@@definfoenclose} command may be used to define a highlighting +command for Info, but not for @TeX{}. A command defined using +@code{@@definfoenclose} marks text by enclosing it in strings that +precede and follow the text. You can use this to get closer control of +your Info output. + +Presumably, if you define a command with @code{@@definfoenclose} for Info, +you will create a corresponding command for @TeX{}, either in +@file{texinfo.tex}, @file{texinfo.cnf}, or within an @samp{@@iftex} in +your document. + +Write a @code{@@definfoenclose} command on a line and follow it with +three arguments separated by commas. The first argument to +@code{@@definfoenclose} is the @@-command name (without the @code{@@}); +the second argument is the Info start delimiter string; and the third +argument is the Info end delimiter string. The latter two arguments +enclose the highlighted text in the Info file. A delimiter string may +contain spaces. Neither the start nor end delimiter is required. If +you do not want a start delimiter but do want an end delimiter, you must +follow the command name with two commas in a row; otherwise, the Info +formatting commands will naturally misinterpret the end delimiter string +you intended as the start delimiter string. + +If you do a @code{@@definfoenclose} on the name of a predefined macro +(such as @code{@@emph}, @code{@@strong}, @code{@@t}, or @code{@@i}), the +enclosure definition will override the built-in definition. + +An enclosure command defined this way takes one argument in braces; this +is intended for new markup commands (@pxref{Marking Text}). + +@findex phoo +For example, you can write: + +@example +@@definfoenclose phoo,//,\\ +@end example + +@noindent +near the beginning of a Texinfo file to define @code{@@phoo} as an Info +formatting command that inserts `//' before and `\\' after the argument +to @code{@@phoo}. You can then write @code{@@phoo@{bar@}} wherever you +want `//bar\\' highlighted in Info. + +Also, for @TeX{} formatting, you could write + +@example +@@iftex +@@global@@let@@phoo=@@i +@@end iftex +@end example + +@noindent +to define @code{@@phoo} as a command that causes @TeX{} to typeset the +argument to @code{@@phoo} in italics. + +Each definition applies to its own formatter: one for @TeX{}, the other +for @code{texinfo-format-buffer} or @code{texinfo-format-region}. The +@code{@@definfoenclose} command need not be within @samp{@@ifinfo}, but +the raw @TeX{} commands do need to be in @samp{@@iftex}. + +@findex headword +Here is another example: write + +@example +@@definfoenclose headword, , : +@end example + +@noindent +near the beginning of the file, to define @code{@@headword} as an Info +formatting command that inserts nothing before and a colon after the +argument to @code{@@headword}. + +@samp{@@definfoenclose} definitions must not be recursive, directly or +indirectly. + + +@node Hardcopy +@chapter Formatting and Printing Hardcopy +@cindex Format and print hardcopy +@cindex Printing hardcopy +@cindex Hardcopy, printing it +@cindex Making a printed manual +@cindex Sorting indices +@cindex Indices, sorting +@cindex @TeX{} index sorting +@pindex texindex + +There are three major shell commands for making a printed manual from a +Texinfo file: one for converting the Texinfo file into a file that will be +printed, a second for sorting indices, and a third for printing the +formatted document. When you use the shell commands, you can either +work directly in the operating system shell or work within a shell +inside GNU Emacs. + +If you are using GNU Emacs, you can use commands provided by Texinfo +mode instead of shell commands. In addition to the three commands to +format a file, sort the indices, and print the result, Texinfo mode +offers key bindings for commands to recenter the output buffer, show the +print queue, and delete a job from the print queue. + +@menu +* Use TeX:: Use @TeX{} to format for hardcopy. +* Format with tex/texindex:: How to format with explicit shell commands. +* Format with texi2dvi:: A simpler way to format. +* Print with lpr:: How to print. +* Within Emacs:: How to format and print from an Emacs shell. +* Texinfo Mode Printing:: How to format and print in Texinfo mode. +* Compile-Command:: How to print using Emacs's compile command. +* Requirements Summary:: @TeX{} formatting requirements summary. +* Preparing for TeX:: What to do before you use @TeX{}. +* Overfull hboxes:: What are and what to do with overfull hboxes. +* smallbook:: How to print small format books and manuals. +* A4 Paper:: How to print on A4 or A5 paper. +* pagesizes:: How to print with customized page sizes. +* Cropmarks and Magnification:: How to print marks to indicate the size + of pages and how to print scaled up output. +* PDF Output:: Portable Document Format output. +* Obtaining TeX:: How to Obtain @TeX{}. +@end menu + +@node Use TeX +@section Use @TeX{} + +The typesetting program called @TeX{} is used for formatting a Texinfo +file. @TeX{} is a very powerful typesetting program and, if used correctly, +does an exceptionally good job. (@xref{Obtaining TeX, , How to Obtain +@TeX{}}, for information on how to obtain @TeX{}.) + +The standalone @code{makeinfo} program and Emacs functions +@code{texinfo-format-region} and @code{texinfo-format-buffer} commands +read the very same @@-commands in the Texinfo file as does @TeX{}, but +process them differently to make an Info file (@pxref{Creating an Info +File}). + + +@node Format with tex/texindex +@section Format with @code{tex} and @code{texindex} +@cindex Shell formatting with @code{tex} and @code{texindex} +@cindex Formatting with @code{tex} and @code{texindex} +@cindex DVI file + +You can format the Texinfo file with the shell command @code{tex} +followed by the name of the Texinfo file. For example: + +@example +tex foo.texi +@end example + +@noindent @TeX{} will produce a @dfn{DVI file} as well as several auxiliary +files containing information for indices, cross references, etc. The +DVI file (for @dfn{DeVice Independent} file) can be printed on virtually +any device (see the following sections). + +@pindex texindex +The @code{tex} formatting command itself does not sort the indices; it +writes an output file of unsorted index data. To generate a printed +index after running the @command{tex} command, you first need a sorted +index to work from. The @command{texindex} command sorts indices. +(The source file @file{texindex.c} comes as part of the standard +Texinfo distribution, among other places.) (@command{texi2dvi} runs +@command{tex} and @command{texindex} as necessary.) + +@cindex Names of index files +@cindex Index file names +The @code{tex} formatting command outputs unsorted index files under +names that obey a standard convention: the name of your main input file +with any @samp{.tex} (or similar, @pxref{tex invocation,,, web2c, +Web2c}) extension removed, followed by the two letter names of indices. +For example, the raw index output files for the input file +@file{foo.texinfo} would be @file{foo.cp}, @file{foo.vr}, @file{foo.fn}, +@file{foo.tp}, @file{foo.pg} and @file{foo.ky}. Those are exactly the +arguments to give to @code{texindex}. + +@need 1000 +@cindex Wildcards +@cindex Globbing +Instead of specifying all the unsorted index file names explicitly, you +can use @samp{??} as shell wildcards and give the command in this +form: + +@example +texindex foo.?? +@end example + +@noindent +This command will run @code{texindex} on all the unsorted index files, +including any that you have defined yourself using @code{@@defindex} +or @code{@@defcodeindex}. (You may execute @samp{texindex foo.??} +even if there are similarly named files with two letter extensions +that are not index files, such as @samp{foo.el}. The @code{texindex} +command reports but otherwise ignores such files.) + +For each file specified, @code{texindex} generates a sorted index file +whose name is made by appending @samp{s} to the input file name. The +@code{@@printindex} command looks for a file with that name +(@pxref{Printing Indices & Menus}). @code{texindex} does not alter the +raw index output file. + +After you have sorted the indices, you need to rerun @code{tex} on the +Texinfo file. This regenerates the DVI file, this time with +up-to-date index entries. + +Finally, you may need to run @code{tex} one more time, to get the page +numbers in the cross-references correct. + +To summarize, this is a five step process: + +@enumerate +@item +Run @code{tex} on your Texinfo file. This generates a DVI file (with +undefined cross-references and no indices), and the raw index files +(with two letter extensions). + +@item +Run @code{texindex} on the raw index files. This creates the +corresponding sorted index files (with three letter extensions). + +@item +Run @code{tex} again on your Texinfo file. This regenerates the DVI +file, this time with indices and defined cross-references, but with page +numbers for the cross-references from last time, generally incorrect. + +@item +Sort the indices again, with @code{texindex}. + +@item +Run @code{tex} one last time. This time the correct page numbers are +written for the cross-references. +@end enumerate + +@pindex texi2dvi +Alternatively, it's a one-step process: run @code{texi2dvi} +(@pxref{Format with texi2dvi}). + +You need not run @code{texindex} each time after you run @code{tex}. If +you do not, on the next run, the @code{tex} formatting command will use +whatever sorted index files happen to exist from the previous use of +@code{texindex}. This is usually ok while you are debugging. + +@cindex Auxiliary files, avoiding +@findex novalidate +@cindex Pointer validation, suppressing +@cindex Chapters, formatting one at a time +Sometimes you may wish to print a document while you know it is +incomplete, or to print just one chapter of a document. In that case, +the usual auxiliary files that @TeX{} creates and warnings @TeX{} gives +when cross-references are not satisfied are just nuisances. You can +avoid them with the @code{@@novalidate} command, which you must give +@emph{before} the @code{@@setfilename} command +(@pxref{setfilename,,@code{@@setfilename}}). Thus, the beginning of +your file would look approximately like this: + +@example +\input texinfo +@@novalidate +@@setfilename myfile.info +@dots{} +@end example + +@noindent @code{@@novalidate} also turns off validation in +@code{makeinfo}, just like its @code{--no-validate} option +(@pxref{Pointer Validation}). + + +@node Format with texi2dvi +@section Format with @code{texi2dvi} +@pindex texi2dvi @r{(shell script)} + +The @code{texi2dvi} command automatically runs both @TeX{} and +@command{texindex} as many times as necessary to produce a DVI file +with sorted indices and all cross-references resolved. It is +therefore simpler than manually executing the +@code{tex}---@code{texindex}---@code{tex}---@code{tex} sequence +described in the previous section. + +To run @code{texi2dvi} on an input file @file{foo.texi}, do this (where +@samp{prompt$ } is your shell prompt): + +@example +prompt$ @kbd{texi2dvi foo.texi} +@end example + +As shown in this example, the input filenames to @code{texi2dvi} must +include any extension (@samp{.texi}, @samp{.texinfo}, etc.). Under +MS-DOS and perhaps in other circumstances, you may need to run @samp{sh +texi2dvi foo.texi} instead of relying on the operating system to invoke +the shell on the @samp{texi2dvi} script. + +@opindex --command @r{(@command{texi2dvi})} +One useful option to @code{texi2dvi} is @samp{--command=@var{cmd}}. +This inserts @var{cmd} on a line by itself after the +@code{@@setfilename} in a temporary copy of the input file before +running @TeX{}. With this, you can specify different printing +formats, such as @code{@@smallbook} (@pxref{smallbook}), +@code{@@afourpaper} (@pxref{A4 Paper}), or @code{@@pagesizes} +(@pxref{pagesizes}), without actually changing the document source. +(You can also do this on a site-wide basis with @file{texinfo.cnf}; +@pxref{Preparing for TeX,,Preparing for @TeX{}}). + +@opindex --pdf @r{(@command{texi2dvi})} +With the @option{--pdf} option, @command{texi2dvi} produces PDF output +instead of DVI (@pxref{PDF Output}), by running @command{pdftex} +instead of @command{tex}. Alternatively, the command +@command{texi2pdf} is an abbreviation for running @samp{texi2dvi +--pdf}. The command @command{pdftexi2dvi} is also supported as a +convenience to AUC-@TeX{} users, since the latter merely prepends +@samp{pdf} to DVI producing tools to have PDF producing tools. + +@cindex @LaTeX{}, processing with @command{texi2dvi} +@command{texi2dvi} can also be used to process @LaTeX{} files; simply +run @samp{texi2dvi filename.ext}. + +@opindex --language @r{(@command{texi2dvi})} +Normally @command{texi2dvi} is able to guess the input file language +by its contents and file name suffix. If, however, it fails to do so +you can specify the input language using +@option{--language=@var{lang}} command line option, where @var{lang} +is either @samp{latex} or @samp{texinfo}. + +@command{texi2dvi} will use @command{etex} (or @command{pdfetex}) if +they are available; these extended versions of @TeX{} are not +required, and the DVI (or PDF) output is identical, but they simplify +the @TeX{} programming in some cases, and provide additional tracing +information when debugging @file{texinfo.tex}. + +@opindex --translate-file @r{(@command{texi2dvi})} +Several options are provided for handling documents, written in +character sets other than ASCII. The +@option{--translate-file=@var{file}} option instructs +@command{texi2dvi} to translate input into internal @TeX{} character +set using @dfn{translation file} @var{file} (@pxref{TCX files, TCX +files, TCX files: Character translations, web2c, Web2c: A @TeX{} +implementation}). + +@opindex --recode @r{(@command{texi2dvi})} +The options @option{--recode} and @option{--recode-from=@var{enc}} +allow conversion of an input document before running @TeX{}. The +@option{--recode} option recodes the document from encoding specified +by @samp{@@documentencoding} command +(@pxref{documentencoding,,@code{documentencoding}}) to plain 7-bit +@samp{texinfo} encoding. + +@opindex --recode-from @r{(@command{texi2dvi})} +The option @option{--recode-from=@var{enc}} recodes the document from +@var{enc} encoding to the encoding specified by +@samp{@@documentencoding}. This is useful, for example, if the +document is written in @samp{UTF-8} encoding and an equivalent 8-bit +encoding is supported by @command{makeinfo}. + +Both @option{--recode} and @option{--recode-from=@var{enc}} use +@command{recode} utility to perform the conversion. If +@command{recode} fails to process the file, @command{texi2dvi} prints +a warning and continues using unmodified input file. + +For a list of other options, run @samp{texi2dvi --help}. + + +@node Print with lpr +@section Shell Print Using @code{lpr -d} +@pindex lpr @r{(DVI print command)} + +The precise command to print a DVI file depends on your system +installation. Two common ones are @samp{dvips foo.dvi -o} and @samp{lpr +-d foo.dvi}. + +For example, the following commands will (perhaps) suffice to sort the +indices, format, and print the @cite{Bison Manual}: + +@example +@group +tex bison.texinfo +texindex bison.?? +tex bison.texinfo +lpr -d bison.dvi +@end group +@end example + +@noindent +(Remember that the shell commands may be different at your site; but +these are commonly used versions.) + +Using the @code{texi2dvi} shell script (see the previous section): + +@example +@group +texi2dvi bison.texinfo +lpr -d bison.dvi +# or perhaps dvips bison.dvi -o +@end group +@end example + +@cindex Shell printing, on MS-DOS/MS-Windows +@cindex Printing DVI files, on MS-DOS/MS-Windows +@pindex lpr@r{-d, replacements on MS-DOS/MS-Windows} +@code{lpr} is a standard program on Unix systems, but it is usually +absent on MS-DOS/MS-Windows. Some network packages come with a +program named @code{lpr}, but these are usually limited to sending files +to a print server over the network, and generally don't support the +@samp{-d} option. If you are unfortunate enough to work on one of these +systems, you have several alternative ways of printing DVI files: + +@itemize @bullet{} +@item Find and install a Unix-like @code{lpr} program, or its clone. +If you can do that, you will be able to print DVI files just like +described above. + +@item Send the DVI files to a network printer queue for DVI files. +Some network printers have special queues for printing DVI files. You +should be able to set up your network software to send files to that +queue. In some cases, the version of @code{lpr} which comes with your +network software will have a special option to send a file to specific +queues, like this: + +@example +lpr -Qdvi -hprint.server.domain bison.dvi +@end example + +@item Convert the DVI file to a Postscript or PCL file and send it to your +local printer. @xref{Invoking Dvips,,, dvips, Dvips}, and the man +pages for @code{dvilj}, for detailed description of these tools. Once +the DVI file is converted to the format your local printer understands +directly, just send it to the appropriate port, usually @samp{PRN}. +@end itemize + + +@node Within Emacs +@section From an Emacs Shell +@cindex Print, format from Emacs shell +@cindex Format, print from Emacs shell +@cindex Shell, format, print from +@cindex Emacs shell, format, print from +@cindex GNU Emacs shell, format, print from + +You can give formatting and printing commands from a shell within GNU +Emacs. To create a shell within Emacs, type @kbd{M-x shell}. In this +shell, you can format and print the document. @xref{Hardcopy, , Format +and Print Hardcopy}, for details. + +You can switch to and from the shell buffer while @code{tex} is +running and do other editing. If you are formatting a long document +on a slow machine, this can be very convenient.@refill + +You can also use @code{texi2dvi} from an Emacs shell. For example, +here is how to use @code{texi2dvi} to format and print @cite{Using and +Porting GNU CC} from a shell within Emacs: + +@example +@group +texi2dvi gcc.texinfo +lpr -d gcc.dvi +@end group +@end example + +See the next section for more information about formatting +and printing in Texinfo mode. + + +@node Texinfo Mode Printing +@section Formatting and Printing in Texinfo Mode +@cindex Region printing in Texinfo mode +@cindex Format and print in Texinfo mode +@cindex Print and format in Texinfo mode + +Texinfo mode provides several predefined key commands for @TeX{} +formatting and printing. These include commands for sorting indices, +looking at the printer queue, killing the formatting job, and +recentering the display of the buffer in which the operations +occur.@refill + +@table @kbd +@item C-c C-t C-b +@itemx M-x texinfo-tex-buffer +Run @code{texi2dvi} on the current buffer.@refill + +@item C-c C-t C-r +@itemx M-x texinfo-tex-region +Run @TeX{} on the current region.@refill + +@item C-c C-t C-i +@itemx M-x texinfo-texindex +Sort the indices of a Texinfo file formatted with +@code{texinfo-tex-region}.@refill + +@item C-c C-t C-p +@itemx M-x texinfo-tex-print +Print a DVI file that was made with @code{texinfo-tex-region} or +@code{texinfo-tex-buffer}.@refill + +@item C-c C-t C-q +@itemx M-x tex-show-print-queue +Show the print queue.@refill + +@item C-c C-t C-d +@itemx M-x texinfo-delete-from-print-queue +Delete a job from the print queue; you will be prompted for the job +number shown by a preceding @kbd{C-c C-t C-q} command +(@code{texinfo-show-tex-print-queue}).@refill + +@item C-c C-t C-k +@itemx M-x tex-kill-job +Kill the currently running @TeX{} job started by either +@code{texinfo-tex-region} or @code{texinfo-tex-buffer}, or any other +process running in the Texinfo shell buffer.@refill + +@item C-c C-t C-x +@itemx M-x texinfo-quit-job +Quit a @TeX{} formatting job that has stopped because of an error by +sending an @key{x} to it. When you do this, @TeX{} preserves a record +of what it did in a @file{.log} file.@refill + +@item C-c C-t C-l +@itemx M-x tex-recenter-output-buffer +Redisplay the shell buffer in which the @TeX{} printing and formatting +commands are run to show its most recent output.@refill +@end table + +@need 1000 +Thus, the usual sequence of commands for formatting a buffer is as +follows (with comments to the right):@refill + +@example +@group +C-c C-t C-b @r{Run @code{texi2dvi} on the buffer.} +C-c C-t C-p @r{Print the DVI file.} +C-c C-t C-q @r{Display the printer queue.} +@end group +@end example + +The Texinfo mode @TeX{} formatting commands start a subshell in Emacs +called the @file{*tex-shell*}. The @code{texinfo-tex-command}, +@code{texinfo-texindex-command}, and @code{tex-dvi-print-command} +commands are all run in this shell. + +You can watch the commands operate in the @samp{*tex-shell*} buffer, +and you can switch to and from and use the @samp{*tex-shell*} buffer +as you would any other shell buffer.@refill + +@need 1500 +The formatting and print commands depend on the values of several variables. +The default values are:@refill + +@example +@group + @r{Variable} @r{Default value} + +texinfo-texi2dvi-command "texi2dvi" +texinfo-tex-command "tex" +texinfo-texindex-command "texindex" +texinfo-delete-from-print-queue-command "lprm" +texinfo-tex-trailer "@@bye" +tex-start-of-header "%**start" +tex-end-of-header "%**end" +tex-dvi-print-command "lpr -d" +tex-show-queue-command "lpq" +@end group +@end example + +You can change the values of these variables with the @kbd{M-x +set-variable} command (@pxref{Examining, , Examining and Setting +Variables, emacs, The GNU Emacs Manual}), or with your @file{.emacs} +initialization file (@pxref{Init File, , , emacs, The GNU Emacs +Manual}). + +@cindex Customize Emacs package (@t{Development/Docs/Texinfo}) +Beginning with version 20, GNU Emacs offers a user-friendly interface, +called @dfn{Customize}, for changing values of user-definable variables. +@xref{Easy Customization, , Easy Customization Interface, emacs, The GNU +Emacs Manual}, for more details about this. The Texinfo variables can +be found in the @samp{Development/Docs/Texinfo} group, once you invoke +the @kbd{M-x customize} command. + + +@node Compile-Command +@section Using the Local Variables List +@cindex Local variables +@cindex Compile command for formatting +@cindex Format with the compile command + +Yet another way to apply the @TeX{} formatting command to a Texinfo file +is to put that command in a @dfn{local variables list} at the end of the +Texinfo file. You can then specify the @code{tex} or @code{texi2dvi} +commands as a @code{compile-command} and have Emacs run it by typing +@kbd{M-x compile}. This creates a special shell called the +@file{*compilation*} buffer in which Emacs runs the compile command. +For example, at the end of the @file{gdb.texinfo} file, after the +@code{@@bye}, you could put the following:@refill + +@example +@group +Local Variables: +compile-command: "texi2dvi gdb.texinfo" +End: +@end group +@end example + +@noindent +This technique is most often used by programmers who also compile programs +this way; see @ref{Compilation, , , emacs, The GNU Emacs Manual}.@refill + + +@node Requirements Summary +@section @TeX{} Formatting Requirements Summary +@cindex Requirements for formatting +@cindex Minimal requirements for formatting +@cindex Formatting requirements + +Every Texinfo file that is to be input to @TeX{} must begin with a +@code{\input} command and must contain an @code{@@setfilename} command: + +@example +\input texinfo +@@setfilename @var{arg-not-used-by-@TeX{}} +@end example + +@noindent +The first command instructs @TeX{} to load the macros it needs to +process a Texinfo file and the second command opens auxiliary files. + +Every Texinfo file must end with a line that terminates @TeX{}'s +processing and forces out unfinished pages: + +@example +@@bye +@end example + +Strictly speaking, these lines are all a Texinfo file needs to be +processed successfully by @TeX{}. + +Usually, however, the beginning includes an @code{@@settitle} command to +define the title of the printed manual, an @code{@@setchapternewpage} +command, a title page, a copyright page, and permissions. Besides an +@code{@@bye}, the end of a file usually includes indices and a table of +contents. (And of course most manuals contain a body of text as well.) + +For more information, see: + +@itemize @bullet +@item @ref{settitle, , @code{@@settitle}}. +@item @ref{setchapternewpage, , @code{@@setchapternewpage}}. +@item @ref{Headings, ,Page Headings}. +@item @ref{Titlepage & Copyright Page}. +@item @ref{Printing Indices & Menus}. +@item @ref{Contents}. +@end itemize + + +@node Preparing for TeX +@section Preparing for @TeX{} +@cindex Preparing for @TeX{} +@cindex @TeX{} input initialization +@cindex @b{.profile} initialization file +@cindex @b{.cshrc} initialization file +@cindex Initialization file for @TeX{} input + +@TeX{} needs to know where to find the @file{texinfo.tex} file that the +@samp{\input texinfo} command on the first line reads. The +@file{texinfo.tex} file tells @TeX{} how to handle @@-commands; it is +included in all standard GNU distributions. The latest version is +always available from the Texinfo source repository: +@smalldisplay +@uref{http://savannah.gnu.org/cgi-bin/viewcvs/texinfo/texinfo/doc/texinfo.tex?rev=HEAD} +@end smalldisplay + +@pindex texinfo.tex@r{, installing} + +Usually, the installer has put the @file{texinfo.tex} file in the +default directory that contains @TeX{} macros when GNU Texinfo, Emacs or +other GNU software is installed. In this case, @TeX{} will find the +file and you do not need to do anything special. If this has not been +done, you can put @file{texinfo.tex} in the current directory when you +run @TeX{}, and @TeX{} will find it there. + +@pindex epsf.tex@r{, installing} +Also, you should install @file{epsf.tex}, if it is not already installed +from another distribution. More details are at the end of the description +of the @code{@@image} command (@pxref{Images}). + +@cindex European Computer Modern fonts, installing +@cindex EC fonts, installing +@cindex CM-Super fonts, installing +To be able to use quotation marks other than those used in English +you'll need to install European Computer Modern fonts and optionally +CM-Super fonts, unless they are already installed (@pxref{Inserting +Quotation Marks}). + +@pindex feymr10@r{, installing} +@cindex Euro font, installing +If you intend to use the @code{@@euro} command, you should install the +Euro font, if it is not already installed. @xref{euro}. + +@pindex texinfo.cnf @r{installation} +@cindex Customizing of @TeX{} for Texinfo +@cindex Site-wide Texinfo configuration file +Optionally, you may create an additional @file{texinfo.cnf}, and install +it as well. This file is read by @TeX{} when the @code{@@setfilename} +command is executed (@pxref{setfilename,, @code{@@setfilename}}). You can put any +commands you like there, according to local site-wide conventions. They +will be read by @TeX{} when processing any Texinfo document. For +example, if @file{texinfo.cnf} contains the line @samp{@@afourpaper} +(@pxref{A4 Paper}), then all Texinfo documents will be processed with +that page size in effect. If you have nothing to put in +@file{texinfo.cnf}, you do not need to create it. + +@cindex Environment variable @code{TEXINPUTS} +@vindex TEXINPUTS +If neither of the above locations for these system files suffice for +you, you can specify the directories explicitly. For +@file{texinfo.tex}, you can do this by writing the complete path for the +file after the @code{\input} command. Another way, that works for both +@file{texinfo.tex} and @file{texinfo.cnf} (and any other file @TeX{} +might read), is to set the @code{TEXINPUTS} environment variable in your +@file{.cshrc} or @file{.profile} file. + +Which you use of @file{.cshrc} or @file{.profile} depends on +whether you use a Bourne shell-compatible (@code{sh}, @code{bash}, +@code{ksh}, @dots{}) or C shell-compatible (@code{csh}, @code{tcsh}) +command interpreter. The latter read the @file{.cshrc} file for +initialization information, and the former read @file{.profile}. + +In a @file{.cshrc} file, you could use the following @code{csh} command +sequence: + +@example +setenv TEXINPUTS .:/home/me/mylib: +@end example + +@need 1000 +In a @file{.profile} file, you could use the following @code{sh} command +sequence: + +@example +@group +TEXINPUTS=.:/home/me/mylib: +export TEXINPUTS +@end group +@end example + +On MS-DOS/MS-Windows, you would say it like this@footnote{Note the use +of the @samp{;} character, instead of @samp{:}, as directory separator +on these systems.}: + +@example +@group +set TEXINPUTS=.;d:/home/me/mylib;c: +@end group +@end example + +@noindent +It is customary for DOS/Windows users to put such commands in the +@file{autoexec.bat} file, or in the Windows Registry. + +@noindent +These settings would cause @TeX{} to look for @file{\input} file first +in the current directory, indicated by the @samp{.}, then in a +hypothetical user @samp{me}'s @file{mylib} directory, and finally in +the system directories. (A leading, trailing, or doubled @samp{:} +indicates searching the system directories at that point.) + +@cindex Dumping a .fmt file +@cindex Format file, dumping +Finally, you may wish to dump a @file{.fmt} file (@pxref{Memory dumps,,, +web2c, Web2c}) so that @TeX{} can load Texinfo faster. (The +disadvantage is that then updating @file{texinfo.tex} requires +redumping.) You can do this by running this command, assuming +@file{epsf.tex} is findable by @TeX{}: + +@example +initex texinfo @@dump +@end example + +@noindent +(@code{dump} is a @TeX{} primitive.) Then, move @file{texinfo.fmt} to +wherever your @code{.fmt} files are found; typically, this will be in the +subdirectory @file{web2c} of your @TeX{} installation. + + +@node Overfull hboxes +@section Overfull ``hboxes'' +@cindex Overfull @samp{hboxes} +@cindex @samp{hboxes}, overfull +@cindex Final output + +@TeX{} is sometimes unable to typeset a line without extending it into +the right margin. This can occur when @TeX{} comes upon what it +interprets as a long word that it cannot hyphenate, such as an +electronic mail network address or a very long title. When this +happens, @TeX{} prints an error message like this: + +@example +Overfull @@hbox (20.76302pt too wide) +@end example + +@findex hbox +@noindent +(In @TeX{}, lines are in ``horizontal boxes'', hence the term, ``hbox''. +@samp{@@hbox} is a @TeX{} primitive not needed in the Texinfo language.) + +@TeX{} also provides the line number in the Texinfo source file and +the text of the offending line, which is marked at all the places that +@TeX{} considered hyphenation. +@xref{Debugging with TeX, , Catching Errors with @TeX{} Formatting}, +for more information about typesetting errors. + +If the Texinfo file has an overfull hbox, you can rewrite the sentence +so the overfull hbox does not occur, or you can decide to leave it. A +small excursion into the right margin often does not matter and may not +even be noticeable. + +If you have many overfull boxes and/or an antipathy to rewriting, you +can coerce @TeX{} into greatly increasing the allowable interword +spacing, thus (if you're lucky) avoiding many of the bad line breaks, +like this: + +@findex \emergencystretch +@example +@@tex +\global\emergencystretch = .9\hsize +@@end tex +@end example + +@noindent +(You should adjust the fraction as needed.) This huge value for +@code{\emergencystretch} cannot be the default, since then the typeset +output would generally be of noticeably lower quality; the default +is @samp{.15\hsize}. @code{\hsize} is the @TeX{} dimension +containing the current line width. + +@cindex Black rectangle in hardcopy +@cindex Rectangle, black in hardcopy +@cindex Box, ugly black in hardcopy +@cindex Ugly black rectangles in hardcopy +For what overfull boxes you have, however, @TeX{} will print a large, +ugly, black rectangle beside the line that contains the overfull hbox +unless told otherwise. This is so you will notice the location of the +problem if you are correcting a draft. + +@findex finalout +To prevent such a monstrosity from marring your final printout, write +the following in the beginning of the Texinfo file on a line of its own, +before the @code{@@titlepage} command: + +@example +@@finalout +@end example + + +@node smallbook +@section Printing ``Small'' Books +@findex smallbook +@cindex Small book size +@cindex Book, printing small +@cindex Page sizes for books +@cindex Size of printed book + +By default, @TeX{} typesets pages for printing in an 8.5 by 11 inch +format. However, you can direct @TeX{} to typeset a document in a 7 by +9.25 inch format that is suitable for bound books by inserting the +following command on a line by itself at the beginning of the Texinfo +file, before the title page:@refill + +@example +@@smallbook +@end example + +@noindent +(Since many books are about 7 by 9.25 inches, this command might better +have been called the @code{@@regularbooksize} command, but it came to be +called the @code{@@smallbook} command by comparison to the 8.5 by 11 +inch format.) + +If you write the @code{@@smallbook} command between the +start-of-header and end-of-header lines, the Texinfo mode @TeX{} +region formatting command, @code{texinfo-tex-region}, will format the +region in ``small'' book size (@pxref{Start of Header}).@refill + +@xref{small}, for information about +commands that make it easier to produce examples for a smaller manual. + +@xref{Format with texi2dvi}, and @ref{Preparing for TeX,,Preparing for +@TeX{}}, for other ways to format with @code{@@smallbook} that do not +require changing the source file. + + +@node A4 Paper +@section Printing on A4 Paper +@cindex A4 paper, printing on +@cindex A5 paper, printing on +@cindex Paper size, A4 +@cindex European A4 paper +@findex afourpaper + +You can tell @TeX{} to format a document for printing on European size +A4 paper (or A5) with the @code{@@afourpaper} (or @code{@@afivepaper}) +command. Write the command on a line by itself near the beginning of +the Texinfo file, before the title page. For example, this is how you +would write the header for this manual: + +@example +@group +\input texinfo @@c -*-texinfo-*- +@@c %**start of header +@@setfilename texinfo +@@settitle Texinfo +@@afourpaper +@@c %**end of header +@end group +@end example + +@xref{Format with texi2dvi}, and @ref{Preparing for TeX,,Preparing for +@TeX{}}, for other ways to format for different paper sizes that do not +require changing the source file. + +@findex afourlatex +@findex afourwide +You may or may not prefer the formatting that results from the command +@code{@@afourlatex}. There's also @code{@@afourwide} for A4 paper in +wide format. + +@node pagesizes +@section @code{@@pagesizes} [@var{width}][, @var{height}]: Custom Page Sizes +@findex pagesizes +@cindex Custom page sizes +@cindex Page sizes, customized +@cindex Text width and height +@cindex Width of text area +@cindex Height of text area +@cindex Depth of text area + +You can explicitly specify the height and (optionally) width of the main +text area on the page with the @code{@@pagesizes} command. Write this +on a line by itself near the beginning of the Texinfo file, before the +title page. The height comes first, then the width if desired, +separated by a comma. Examples: + +@example +@@pagesizes 200mm,150mm @c for b5 paper +@end example +@noindent and +@example +@@pagesizes 11.5in @c for legal paper +@end example + +@cindex B5 paper, printing on +@cindex Legal paper, printing on +This would be reasonable for printing on B5-size paper. To emphasize, +this command specifies the size of the @emph{text area}, not the size of +the paper (which is 250@dmn{mm} by 177@dmn{mm} for B5, 14@dmn{in} by +8.5@dmn{in} for legal). + +@cindex Margins on page, not controllable +To make more elaborate changes, such as changing any of the page +margins, you must define a new command in @file{texinfo.tex} (or +@file{texinfo.cnf}, @pxref{Preparing for TeX,,Preparing for @TeX{}}). + +@xref{Format with texi2dvi}, and @ref{Preparing for TeX,,Preparing for +@TeX{}}, for other ways to specify @code{@@pagesizes} that do not +require changing the source file. + +@code{@@pagesizes} is ignored by @code{makeinfo}. + + +@node Cropmarks and Magnification +@section Cropmarks and Magnification +@findex cropmarks +@cindex Cropmarks for printing +@cindex Printing cropmarks +You can (attempt to) direct @TeX{} to print cropmarks at the corners of +pages with the @code{@@cropmarks} command. Write the @code{@@cropmarks} +command on a line by itself between @code{@@iftex} and @code{@@end +iftex} lines near the beginning of the Texinfo file, before the title +page, like this:@refill + +@example +@group +@@iftex +@@cropmarks +@@end iftex +@end group +@end example + +This command is mainly for printers that typeset several pages on one +sheet of film; but you can attempt to use it to mark the corners of a +book set to 7 by 9.25 inches with the @code{@@smallbook} command. +(Printers will not produce cropmarks for regular sized output that is +printed on regular sized paper.) Since different printing machines work +in different ways, you should explore the use of this command with a +spirit of adventure. You may have to redefine the command in +@file{texinfo.tex}. + +@findex \mag @r{(raw @TeX{} magnification)} +@cindex Magnified printing +@cindex Larger or smaller pages +You can attempt to direct @TeX{} to typeset pages larger or smaller than +usual with the @code{\mag} @TeX{} command. Everything that is typeset +is scaled proportionally larger or smaller. (@code{\mag} stands for +``magnification''.) This is @emph{not} a Texinfo @@-command, but is a +plain @TeX{} command that is prefixed with a backslash. You have to +write this command between @code{@@tex} and @code{@@end tex} +(@pxref{Raw Formatter Commands}). + +Follow the @code{\mag} command with an @samp{=} and then a number that +is 1000 times the magnification you desire. For example, to print pages +at 1.2 normal size, write the following near the beginning of the +Texinfo file, before the title page: + +@example +@group +@@tex +\mag=1200 +@@end tex +@end group +@end example + +With some printing technologies, you can print normal-sized copies that +look better than usual by giving a larger-than-normal master to your +print shop. They do the reduction, thus effectively increasing the +resolution. + +Depending on your system, DVI files prepared with a +nonstandard-@code{\mag} may not print or may print only with certain +magnifications. Be prepared to experiment. + + +@node PDF Output +@section PDF Output +@cindex PDF output + +@pindex pdftex +The simplest way to generate PDF output from Texinfo source is to run +the convenience script @command{texi2pdf} (or @command{pdftexi2dvi}); +this simply executes the @command{texi2dvi} script with the +@option{--pdf} option (@pxref{Format with texi2dvi}). If for some +reason you want to process the document by hand, simply run the +@command{pdftex} program instead of plain @command{tex}. That is, run +@samp{pdftex foo.texi} instead of @samp{tex foo.texi}. + +@dfn{PDF} stands for `Portable Document Format'. It was invented by +Adobe Systems some years ago for document interchange, based on their +PostScript language. Related links: + +@itemize +@item +GNU GV, a @uref{http://www.foolabs.com/xpdf/, Ghostscript-based PDF +reader}. (It can also preview PostScript documents.) + +@item +A freely available standalone @uref{http://www.foolabs.com/xpdf/, +PDF reader} for the X window system. + +@item +@uref{http://partners.adobe.com/asn/acrobat/sdk/public/docs/, PDF definition}. + +@end itemize + +At present, Texinfo does not provide +@samp{@@ifpdf} or @samp{@@pdf} commands as for the other output +formats, since PDF documents contain many internal links that would be +hard or impossible to get right at the Texinfo source level. + +PDF files require special software to be displayed, unlike the plain +ASCII formats (Info, HTML) that Texinfo supports. They also tend to +be much larger than the DVI files output by @TeX{} by default. +Nevertheless, a PDF file does define an actual typeset document in a +self-contained file, so it has its place. + + +@node Obtaining TeX +@section How to Obtain @TeX{} +@cindex Obtaining @TeX{} +@cindex @TeX{}, how to obtain + +@c !!! Here is information about obtaining TeX. Update it whenever. +@c !!! Also consider updating TeX.README on ftp.gnu.org. +@c Updated by RJC on 1 March 1995, conversation with MacKay. +@c Updated by kb@cs.umb.edu on 29 July 1996. +@c Updated by kb@cs.umb.edu on 25 April 1997. +@c Updated by kb@cs.umb.edu on 27 February 1998. +@TeX{} is freely redistributable. You can obtain @TeX{} for Unix +systems via anonymous ftp or on physical media. The core material +consists of the Web2c @TeX{} distribution (@uref{http://tug.org/web2c}). + +Instructions for retrieval by anonymous ftp and information on other +available distributions: +@uref{http://tug.org/unixtex.ftp}. + +The Free Software Foundation provides a core distribution on its Source +Code CD-ROM suitable for printing Texinfo manuals. To order it, contact: + +@display +@group +Free Software Foundation, Inc. +51 Franklin St, Fifth Floor +Boston, MA @ @ 02110-1301 +USA +Telephone: @w{+1-617-542-5942} +Fax: (including Japan) @w{+1-617-542-2652} +Free Dial Fax (in Japan): +@w{ } @w{ } @w{ } 0031-13-2473 (KDD) +@w{ } @w{ } @w{ } 0066-3382-0158 (IDC) +Electronic mail: @code{gnu@@gnu.org} +@end group +@end display + +Many other @TeX{} distributions are available; see +@uref{http://tug.org/}. + + +@node Creating and Installing Info Files +@chapter Creating and Installing Info Files + +This chapter describes how to create and install Info files. @xref{Info +Files}, for general information about the file format itself. + +@menu +* Creating an Info File:: +* Installing an Info File:: +@end menu + + +@node Creating an Info File +@section Creating an Info File +@cindex Creating an Info file +@cindex Info, creating an online file +@cindex Formatting a file for Info + +@code{makeinfo} is a program that converts a Texinfo file into an Info +file, HTML file, or plain text. @code{texinfo-format-region} and +@code{texinfo-format-buffer} are GNU Emacs functions that convert +Texinfo to Info. + +For information on installing the Info file in the Info system, +@pxref{Installing an Info File}. + +@menu +* makeinfo advantages:: @code{makeinfo} provides better error checking. +* Invoking makeinfo:: How to run @code{makeinfo} from a shell. +* makeinfo options:: Specify fill-column and other options. +* Pointer Validation:: How to check that pointers point somewhere. +* makeinfo in Emacs:: How to run @code{makeinfo} from Emacs. +* texinfo-format commands:: Two Info formatting commands written + in Emacs Lisp are an alternative + to @code{makeinfo}. +* Batch Formatting:: How to format for Info in Emacs Batch mode. +* Tag and Split Files:: How tagged and split files help Info + to run better. +@end menu + + +@node makeinfo advantages +@subsection @code{makeinfo} Preferred + +The @code{makeinfo} utility creates an Info file from a Texinfo source +file more quickly than either of the Emacs formatting commands and +provides better error messages. We recommend it. @code{makeinfo} is a +C program that is independent of Emacs. You do not need to run Emacs to +use @code{makeinfo}, which means you can use @code{makeinfo} on machines +that are too small to run Emacs. You can run @code{makeinfo} in any one +of three ways: from an operating system shell, from a shell inside +Emacs, or by typing the @kbd{C-c C-m C-r} or the @kbd{C-c C-m C-b} +command in Texinfo mode in Emacs. + +The @code{texinfo-format-region} and the @code{texinfo-format-buffer} +commands are useful if you cannot run @code{makeinfo}. Also, in some +circumstances, they format short regions or buffers more quickly than +@code{makeinfo}. + + +@node Invoking makeinfo +@subsection Running @code{makeinfo} from a Shell +@pindex makeinfo + +To create an Info file from a Texinfo file, invoke @command{makeinfo} +followed by the name of the Texinfo file. Thus, to create the Info +file for Bison, type the following to the shell: + +@example +makeinfo bison.texinfo +@end example + +(You can run a shell inside Emacs by typing @kbd{M-x shell}.) + +@command{makeinfo} has many options to control its actions and output; +see the next section. + +You can give @command{makeinfo} more than one input file name; each is +processed in turn. If an input file name is @samp{-}, or no input +file names are given at all, standard input is read. + + +@node makeinfo options +@subsection Options for @code{makeinfo} +@cindex @code{makeinfo} options +@cindex Options for @code{makeinfo} + +The @command{makeinfo} program accepts many options. Perhaps the most +commonly needed are those that change the output format. By default, +@command{makeinfo} outputs Info files. + +Each command line option is a word preceded by @samp{--} or a letter +preceded by @samp{-}. You can use abbreviations for the long option +names as long as they are unique. + +For example, you could use the following shell command to create an Info +file for @file{bison.texinfo} in which each line is filled to only 68 +columns: + +@example +makeinfo --fill-column=68 bison.texinfo +@end example + +You can write two or more options in sequence, like this:@refill + +@example +makeinfo --no-split --fill-column=70 @dots{} +@end example + +@noindent +This would keep the Info file together as one possibly very long +file and would also set the fill column to 70. + +The options are: + +@table @code + +@item -D @var{var} +@opindex -D @var{var} +Cause the variable @var{var} to be defined. This is equivalent to +@code{@@set @var{var}} in the Texinfo file (@pxref{set clear value}). + +@item --commands-in-node-names +@opindex --commands-in-node-names +Allow @code{@@}-commands in node names. This is not recommended, as it +can probably never be implemented in @TeX{}. It also makes +@code{makeinfo} much slower. Also, this option is ignored when +@samp{--no-validate} is used. @xref{Pointer Validation}, for more +details. + +@item --css-include=@var{file} +@opindex --css-include +Include the contents of @var{file}, which should contain cascading +style sheets specifications, in the @samp{<style>} block of the HTML +output. @xref{HTML CSS}. If @var{file} is @samp{-}, read standard +input. + +@item --css-ref=@var{url} +@opindex --css-ref +In HTML mode, add a @samp{<link>} tag to the HTML output which +references a cascading style sheet at @var{url}. This allows using +standalone style sheets. + +@item --disable-encoding +@itemx --enable-encoding +@opindex --disable-encoding +@opindex --enable-encoding +By default, or with @option{--enable-encoding}, output accented and +special characters in Info or plain text output based on +@samp{@@documentencoding}. With @option{--disable-encoding}, 7-bit +ASCII transliterations are output. +@xref{documentencoding,,@code{documentencoding}}, and @ref{Inserting +Accents}. + +@item --docbook +@opindex --docbook +Generate Docbook output rather than Info. + +@item --document-language=@var{lang} +@opindex --document-language +@vindex LANG +Use @var{lang} to translate Texinfo keywords which end up in the +output document. The default is the locale specified by the +@code{@@documentlanguage} command if there is one +(@pxref{documentlanguage}). + +@item --error-limit=@var{limit} +@itemx -e @var{limit} +@opindex --error-limit=@var{limit} +@opindex -e @var{limit} +Set the maximum number of errors that @code{makeinfo} will report +before exiting (on the assumption that continuing would be useless); +default 100. + +@item --fill-column=@var{width} +@itemx -f @var{width} +@opindex --fill-column=@var{width} +@opindex -f @var{width} +Specify the maximum number of columns in a line; this is the right-hand +edge of a line. Paragraphs that are filled will be filled to this +width. (Filling is the process of breaking up and connecting lines so +that lines are the same length as or shorter than the number specified +as the fill column. Lines are broken between words.) The default value +is 72. Ignored with @samp{--html}. + +@item --footnote-style=@var{style} +@itemx -s @var{style} +@opindex --footnote-style=@var{style} +@opindex -s @var{style} +Set the footnote style to @var{style}, either @samp{end} for the end +node style (the default) or @samp{separate} for the separate node style. +The value set by this option overrides the value set in a Texinfo file +by an @code{@@footnotestyle} command (@pxref{Footnotes}). When the +footnote style is @samp{separate}, @code{makeinfo} makes a new node +containing the footnotes found in the current node. When the footnote +style is @samp{end}, @code{makeinfo} places the footnote references at +the end of the current node. Ignored with @samp{--html}. + +@item --force +@itemx -F +@opindex --force +@opindex -F +Ordinarily, if the input file has errors, the output files are not +created. With this option, they are preserved. + +@item --help +@itemx -h +@opindex --help +@opindex -h +Print a usage message listing all available options, then exit successfully. + +@item --html +@opindex --html +Generate HTML output rather than Info. @xref{Generating HTML}. By +default, the HTML output is split into one output file per Texinfo +source node, and the split output is written into a subdirectory with +the name of the top-level info file. + +@item -I @var{dir} +@opindex -I @var{dir} +Append @var{dir} to the directory search list for finding files that +are included using the @code{@@include} command. By default, +@code{makeinfo} searches only the current directory. If @var{dir} is +not given, the current directory @file{.} is appended. Note that +@var{dir} can actually be a list of several directories separated by the +usual path separator character (@samp{:} on Unix, @samp{;} on +MS-DOS/MS-Windows). + +@item --ifdocbook +@opindex --ifdocbook +@itemx --ifhtml +@opindex --ifhtml +@itemx --ifinfo +@opindex --ifinfo +@itemx --ifplaintext +@opindex --ifplaintext +@itemx --iftex +@opindex --iftex +@itemx --ifxml +@opindex --ifxml +For the specified format, process @samp{@@if@var{format}} and +@samp{@@@var{format}} commands even if not generating the given output +format. For instance, if @option{--iftex} is specified, then +@samp{@@iftex} and @samp{@@tex} blocks will be read. + +@item --internal-links=@var{file} +@opindex --internal-links=@var{file} +In HTML mode, output a tab separated file containing three columns: +the internal link to an indexed item or item in the table of contents, +the name of the index (or "toc") in which it occurs, and the term +which was indexed or entered. + +@item --macro-expand=@var{file} +@itemx -E @var{file} +@opindex --macro-expand=@var{file} +@opindex -E @var{file} +Output the Texinfo source with all the macros expanded to the named +file. Normally, the results of macro expansion are used internally by +@code{makeinfo} and then discarded. This option is used by +@command{texi2dvi}. + +@item --no-headers +@item --plaintext +@opindex --no-headers +@opindex --plaintext +@cindex Plain text output +@cindex ASCII text output +@cindex Generating plain text files +@cindex @file{INSTALL} file, generating +@cindex Node separators, omitting +@cindex Menus, omitting +Do not include menus or node separator lines in the output, and +implicitly @option{--enable-encoding} (see above). This results in a +simple plain text file that you can (for example) send in email +without complications, or include in a distribution (as in an +@file{INSTALL} file). + +@cindex Navigation links, omitting +For HTML output, likewise omit menus. And if @samp{--no-split} is also +specified, do not include a navigation links at the top of each node +(these are never included in the default case of split output). +@xref{Generating HTML}. + +In both cases, ignore @code{@@setfilename} and write to standard +output by default---can be overridden with @option{-o}. + +@item --no-ifdocbook +@opindex --no-ifdocbook +@itemx --no-ifhtml +@opindex --no-ifhtml +@itemx --no-ifinfo +@opindex --no-ifinfo +@itemx --no-ifplaintext +@opindex --no-ifplaintext +@itemx --no-iftex +@opindex --no-iftex +@itemx --no-ifxml +@opindex --no-ifxml +Do not process @samp{@@if@var{format}} and @samp{@@@var{format}} +commands, and do process @samp{@@ifnot@var{format}}, even if +generating the given format. For instance, if @option{--no-ifhtml} is +specified, then @samp{@@ifhtml} and @samp{@@html} blocks will not be +read, and @samp{@@ifnothtml} blocks will be. + +@item --no-number-footnotes +@opindex --no-number-footnotes +Suppress automatic footnote numbering. By default, @code{makeinfo} +numbers each footnote sequentially in a single node, resetting the +current footnote number to 1 at the start of each node. + +@item --no-number-sections +@opindex --no-number-sections +Do not output chapter, section, and appendix numbers. +You need to specify this if your manual is not hierarchically-structured. + +@item --no-split +@opindex --no-split +@cindex Splitting of output files +@cindex Output file splitting +Suppress the splitting stage of @code{makeinfo}. By default, large +output files (where the size is greater than 70k bytes) are split into +smaller subfiles. For Info output, each one is approximately 50k bytes. +For HTML output, each file contains one node (@pxref{Generating HTML}). + +@item --no-pointer-validate +@itemx --no-validate +@opindex --no-pointer-validate +@opindex --no-validate +@cindex Pointer validation, suppressing +Suppress the pointer-validation phase of @code{makeinfo}---a dangerous +thing to do. This can also be done with the @code{@@novalidate} +command (@pxref{Use TeX,,Use @TeX{}}). Normally, after a Texinfo file +is processed, some consistency checks are made to ensure that cross +references can be resolved, etc. @xref{Pointer Validation}. + +@item --no-warn +@opindex --no-warn +Suppress warning messages (but @emph{not} error messages). + +@item --number-sections +@opindex --number-sections +Output chapter, section, and appendix numbers as in printed manuals. +This is the default. It works only with hierarchically-structured +manuals. + +@item --output=@var{file} +@itemx -o @var{file} +@opindex --output=@var{file} +@opindex -o @var{file} +Specify that the output should be directed to @var{file} and not to the +file name specified in the @code{@@setfilename} command found in the +Texinfo source (@pxref{setfilename}). If @var{file} is @samp{-}, output +goes to standard output and @samp{--no-split} is implied. For split +HTML output, @var{file} is the name for the directory into which all +HTML nodes are written (@pxref{Generating HTML}). + +@item -P @var{dir} +@opindex -P @var{dir} +Prepend @var{dir} to the directory search list for @code{@@include}. +If @var{dir} is not given, the current directory @file{.} is prepended. +See @samp{-I} for more details. + +@item --paragraph-indent=@var{indent} +@itemx -p @var{indent} +@opindex --paragraph-indent=@var{indent} +@opindex -p @var{indent} +Set the paragraph indentation style to @var{indent}. The value set by +this option overrides the value set in a Texinfo file by an +@code{@@paragraphindent} command (@pxref{paragraphindent}). The value +of @var{indent} is interpreted as follows: + +@table @asis +@item @samp{asis} +Preserve any existing indentation at the starts of paragraphs. + +@item @samp{0} or @samp{none} +Delete any existing indentation. + +@item @var{num} +Indent each paragraph by @var{num} spaces. +@end table + +@item --split-size=@var{num} +@opindex --split-size=@var{num} +Keep Info files to at most @var{num} characters; default is 300,000. + +@item --transliterate-file-names +@opindex --transliterate-file-names +Enable transliteration of 8-bit characters in node names for the +purpose of file name creation. @xref{HTML Xref 8-bit Character Expansion}. + +@item -U @var{var} +Cause @var{var} to be undefined. This is equivalent to +@code{@@clear @var{var}} in the Texinfo file (@pxref{set clear value}). + +@item --verbose +@opindex --verbose +Cause @code{makeinfo} to display messages saying what it is doing. +Normally, @code{makeinfo} only outputs messages if there are errors or +warnings. + +@item --version +@itemx -V +@opindex --version +@opindex -V +Print the version number, then exit successfully. + +@item --xml +@opindex --xml +Generate XML output rather than Info. + +@end table + +@vindex TEXINFO_OUTPUT_FORMAT +@cindex Environment variable @code{TEXINFO_OUTPUT_FORMAT} +@command{makeinfo} also reads the environment variable +@env{TEXINFO_OUTPUT_FORMAT} to determine the output format, if not +overridden by a command line option. The possible values are: + +@example +docbook html info plaintext xml +@end example + +If not set, Info output is the default. + + +@node Pointer Validation +@subsection Pointer Validation +@cindex Pointer validation with @code{makeinfo} +@cindex Validation of pointers + +If you do not suppress pointer validation with the @samp{--no-validate} +option or the @code{@@novalidate} command in the source file (@pxref{Use +TeX,,Use @TeX{}}), @code{makeinfo} will check the validity of the final +Info file. Mostly, this means ensuring that nodes you have referenced +really exist. Here is a complete list of what is checked: + +@enumerate +@item +If a `Next', `Previous', or `Up' node reference is a reference to a +node in the current file and is not an external reference such as to +@file{(dir)}, then the referenced node must exist.@refill + +@item +In every node, if the `Previous' node is different from the `Up' node, +then the node pointed to by the `Previous' field must have a `Next' +field which points back to this node.@refill + +@item +Every node except the `Top' node must have an `Up' pointer.@refill + +@item +The node referenced by an `Up' pointer must itself reference the current +node through a menu item, unless the node referenced by `Up' +has the form `(@var{file})'. + +@item +If the `Next' reference of a node is not the same as the `Next' reference +of the `Up' reference, then the node referenced by the `Next' pointer +must have a `Previous' pointer that points back to the current node. +This rule allows the last node in a section to point to the first node +of the next chapter.@refill + +@item +Every node except `Top' should be referenced by at least one other node, +either via the `Previous' or `Next' links, or via a menu or a +cross-reference.@refill +@end enumerate + +@cindex @@-commands in @@node, limited support +Some Texinfo documents might fail during the validation phase because +they use commands like @code{@@value} and @code{@@definfoenclose} in +node definitions and cross-references inconsistently. (Your best bet +is to avoid using @@-commands in node names.) Consider the +following example: + +@example +@group +@@set nodename Node 1 + +@@node @@value@{nodename@}, Node 2, Top, Top + +This is node 1. + +@@node Node 2, , Node 1, Top + +This is node 2. +@end group +@end example + +@noindent +Here, the node ``Node 1'' was referenced both verbatim and through +@code{@@value}. + +By default, @code{makeinfo} fails such cases, because node names are not +fully expanded until they are written to the output file. You should +always try to reference nodes consistently; e.g., in the above example, +the second @code{@@node} line should have also used @code{@@value}. +However, if, for some reason, you @emph{must} reference node names +inconsistently, and @code{makeinfo} fails to validate the file, you can +use the @samp{--commands-in-node-names} option to force @code{makeinfo} +to perform the expensive expansion of all node names it finds in the +document. This might considerably slow down the program, though; +twofold increase in conversion time was measured for large documents +such as the Jargon file. + +@cindex @@value in @@node lines +The support for @code{@@}-commands in @code{@@node} directives is not +general enough to be freely used. For example, if the example above +redefined @code{nodename} somewhere in the document, @code{makeinfo} +will fail to convert it, even if invoked with the +@samp{--commands-in-node-names} option. + +@samp{--commands-in-node-names} has no effect if the @samp{--no-validate} +option is given. + + +@node makeinfo in Emacs +@subsection Running @code{makeinfo} Within Emacs +@cindex Running @code{makeinfo} in Emacs +@cindex @code{makeinfo} inside Emacs +@cindex Shell, running @code{makeinfo} in + +You can run @code{makeinfo} in GNU Emacs Texinfo mode by using either the +@code{makeinfo-region} or the @code{makeinfo-buffer} commands. In +Texinfo mode, the commands are bound to @kbd{C-c C-m C-r} and @kbd{C-c +C-m C-b} by default.@refill + +@table @kbd +@item C-c C-m C-r +@itemx M-x makeinfo-region +Format the current region for Info.@refill +@findex makeinfo-region + +@item C-c C-m C-b +@itemx M-x makeinfo-buffer +Format the current buffer for Info.@refill +@findex makeinfo-buffer +@end table + +When you invoke @code{makeinfo-region} the output goes to a temporary +buffer. When you invoke @code{makeinfo-buffer} output goes to the +file set with @code{@@setfilename} (@pxref{setfilename}). + +The Emacs @code{makeinfo-region} and @code{makeinfo-buffer} commands +run the @code{makeinfo} program in a temporary shell buffer. If +@code{makeinfo} finds any errors, Emacs displays the error messages in +the temporary buffer.@refill + +@cindex Errors, parsing +@cindex Parsing errors +@findex next-error +You can parse the error messages by typing @kbd{C-x `} +(@code{next-error}). This causes Emacs to go to and position the +cursor on the line in the Texinfo source that @code{makeinfo} thinks +caused the error. @xref{Compilation, , Running @code{make} or +Compilers Generally, emacs, The GNU Emacs Manual}, for more +information about using the @code{next-error} command.@refill + +In addition, you can kill the shell in which the @code{makeinfo} +command is running or make the shell buffer display its most recent +output.@refill + +@table @kbd +@item C-c C-m C-k +@itemx M-x makeinfo-kill-job +@findex makeinfo-kill-job +Kill the current running @code{makeinfo} job +(from @code{makeinfo-region} or @code{makeinfo-buffer}).@refill + +@item C-c C-m C-l +@itemx M-x makeinfo-recenter-output-buffer +@findex makeinfo-recenter-output-buffer +Redisplay the @code{makeinfo} shell buffer to display its most recent +output.@refill +@end table + +@noindent +(Note that the parallel commands for killing and recentering a @TeX{} +job are @kbd{C-c C-t C-k} and @kbd{C-c C-t C-l}. @xref{Texinfo Mode +Printing}.)@refill + +You can specify options for @code{makeinfo} by setting the +@code{makeinfo-options} variable with either the @kbd{M-x +customize} or the @kbd{M-x set-variable} command, or by setting the +variable in your @file{.emacs} initialization file. + +For example, you could write the following in your @file{.emacs} file:@refill + +@example +@group +(setq makeinfo-options + "--paragraph-indent=0 --no-split + --fill-column=70 --verbose") +@end group +@end example + +@noindent +@c If you write these three cross references using xref, you see +@c three references to the same named manual, which looks strange. +@iftex +For more information, see @ref{makeinfo options, , Options for +@code{makeinfo}}, as well as ``Easy Customization Interface,'' ``Examining +and Setting Variables,'' and ``Init File'' in @cite{The GNU Emacs +Manual}. +@end iftex +@ifnottex +For more information, see@* +@ref{Easy Customization, , Easy Customization Interface, emacs, The GNU Emacs Manual},@* +@ref{Examining, , Examining and Setting Variables, emacs, The GNU Emacs Manual},@* +@ref{Init File, , , emacs, The GNU Emacs Manual}, and@* +@ref{makeinfo options, , Options for @code{makeinfo}}. +@end ifnottex + +@node texinfo-format commands +@subsection The @code{texinfo-format@dots{}} Commands + +In GNU Emacs in Texinfo mode, you can format part or all of a Texinfo +file with the @code{texinfo-format-region} command. This formats the +current region and displays the formatted text in a temporary buffer +called @samp{*Info Region*}.@refill + +Similarly, you can format a buffer with the +@code{texinfo-format-buffer} command. This command creates a new +buffer and generates the Info file in it. Typing @kbd{C-x C-s} will +save the Info file under the name specified by the +@code{@@setfilename} line which must be near the beginning of the +Texinfo file.@refill + +@table @kbd +@item C-c C-e C-r +@itemx @code{texinfo-format-region} +@findex texinfo-format-region +Format the current region for Info. + +@item C-c C-e C-b +@itemx @code{texinfo-format-buffer} +@findex texinfo-format-buffer +Format the current buffer for Info. +@end table + +The @code{texinfo-format-region} and @code{texinfo-format-buffer} +commands provide you with some error checking, and other functions can +provide you with further help in finding formatting errors. These +procedures are described in an appendix; see @ref{Catching Mistakes}. +However, the @code{makeinfo} program is often faster and +provides better error checking (@pxref{makeinfo in Emacs}).@refill + +@node Batch Formatting +@comment node-name, next, previous, up +@subsection Batch Formatting +@cindex Batch formatting for Info +@cindex Info batch formatting + +You can format Texinfo files for Info using @code{batch-texinfo-format} +and Emacs Batch mode. You can run Emacs in Batch mode from any shell, +including a shell inside of Emacs. (@xref{Command Arguments,,, +emacs, The GNU Emacs Manual}.) + +Here is a shell command to format all the files that end in +@file{.texinfo} in the current directory: + +@example +emacs -batch -funcall batch-texinfo-format *.texinfo +@end example + +@noindent +Emacs processes all the files listed on the command line, even if an +error occurs while attempting to format some of them.@refill + +Run @code{batch-texinfo-format} only with Emacs in Batch mode as shown; +it is not interactive. It kills the Batch mode Emacs on completion.@refill + +@code{batch-texinfo-format} is convenient if you lack @code{makeinfo} +and want to format several Texinfo files at once. When you use Batch +mode, you create a new Emacs process. This frees your current Emacs, so +you can continue working in it. (When you run +@code{texinfo-format-region} or @code{texinfo-format-buffer}, you cannot +use that Emacs for anything else until the command finishes.)@refill + +@node Tag and Split Files +@comment node-name, next, previous, up +@subsection Tag Files and Split Files +@cindex Making a tag table automatically +@cindex Tag table, making automatically + +If a Texinfo file has more than 30,000 bytes, +@code{texinfo-format-buffer} automatically creates a tag table +for its Info file; @code{makeinfo} always creates a tag table. With +a @dfn{tag table}, Info can jump to new nodes more quickly than it can +otherwise.@refill + +@cindex Indirect subfiles +In addition, if the Texinfo file contains more than about 300,000 +bytes, @code{texinfo-format-buffer} and @code{makeinfo} split the +large Info file into shorter @dfn{indirect} subfiles of about 300,000 +bytes each. Big files are split into smaller files so that Emacs does +not need to make a large buffer to hold the whole of a large Info +file; instead, Emacs allocates just enough memory for the small, split-off +file that is needed at the time. This way, Emacs avoids wasting +memory when you run Info. (Before splitting was implemented, Info +files were always kept short and @dfn{include files} were designed as +a way to create a single, large printed manual out of the smaller Info +files. @xref{Include Files}, for more information. Include files are +still used for very large documents, such as @cite{The Emacs Lisp +Reference Manual}, in which each chapter is a separate file.)@refill + +When a file is split, Info itself makes use of a shortened version of +the original file that contains just the tag table and references to +the files that were split off. The split-off files are called +@dfn{indirect} files.@refill + +The split-off files have names that are created by appending @w{@samp{-1}}, +@w{@samp{-2}}, @w{@samp{-3}} and so on to the file name specified by the +@code{@@setfilename} command. The shortened version of the original file +continues to have the name specified by @code{@@setfilename}.@refill + +At one stage in writing this document, for example, the Info file was saved +as the file @file{test-texinfo} and that file looked like this:@refill + +@example +@group +Info file: test-texinfo, -*-Text-*- +produced by texinfo-format-buffer +from file: new-texinfo-manual.texinfo + +^_ +Indirect: +test-texinfo-1: 102 +test-texinfo-2: 50422 +@end group +@group +test-texinfo-3: 101300 +^_^L +Tag table: +(Indirect) +Node: overview^?104 +Node: info file^?1271 +@end group +@group +Node: printed manual^?4853 +Node: conventions^?6855 +@dots{} +@end group +@end example + +@noindent +(But @file{test-texinfo} had far more nodes than are shown here.) Each of +the split-off, indirect files, @file{test-texinfo-1}, +@file{test-texinfo-2}, and @file{test-texinfo-3}, is listed in this file +after the line that says @samp{Indirect:}. The tag table is listed after +the line that says @samp{Tag table:}. @refill + +In the list of indirect files, the number following the file name +records the cumulative number of bytes in the preceding indirect files, +not counting the file list itself, the tag table, or the permissions +text in each file. In the tag table, the number following the node name +records the location of the beginning of the node, in bytes from the +beginning of the (unsplit) output. + +If you are using @code{texinfo-format-buffer} to create Info files, +you may want to run the @code{Info-validate} command. (The +@code{makeinfo} command does such a good job on its own, you do not +need @code{Info-validate}.) However, you cannot run the @kbd{M-x +Info-validate} node-checking command on indirect files. For +information on how to prevent files from being split and how to +validate the structure of the nodes, see @ref{Using Info-validate}. + + +@node Installing an Info File +@section Installing an Info File +@cindex Installing an Info file +@cindex Info file installation +@cindex @file{dir} directory for Info installation + +Info files are usually kept in the @file{info} directory. You can read +Info files using the standalone Info program or the Info reader built +into Emacs. (@inforef{Top, info, info}, for an introduction to Info.) + +@menu +* Directory File:: The top level menu for all Info files. +* New Info File:: Listing a new Info file. +* Other Info Directories:: How to specify Info files that are + located in other directories. +* Installing Dir Entries:: How to specify what menu entry to add + to the Info directory. +* Invoking install-info:: @code{install-info} options. +@end menu + + +@node Directory File +@subsection The Directory File @file{dir} + +For Info to work, the @file{info} directory must contain a file that +serves as a top level directory for the Info system. By convention, +this file is called @file{dir}. (You can find the location of this file +within Emacs by typing @kbd{C-h i} to enter Info and then typing +@kbd{C-x C-f} to see the pathname to the @file{info} directory.) + +The @file{dir} file is itself an Info file. It contains the top level +menu for all the Info files in the system. The menu looks like +this:@refill + +@example +@group +* Menu: +* Info: (info). Documentation browsing system. +* Emacs: (emacs). The extensible, self-documenting + text editor. +* Texinfo: (texinfo). With one source file, make + either a printed manual using + @@TeX@{@} or an Info file. +@dots{} +@end group +@end example + +Each of these menu entries points to the `Top' node of the Info file +that is named in parentheses. (The menu entry does not need to +specify the `Top' node, since Info goes to the `Top' node if no node +name is mentioned. @xref{Other Info Files, , Nodes in Other Info +Files}.)@refill + +Thus, the @samp{Info} entry points to the `Top' node of the +@file{info} file and the @samp{Emacs} entry points to the `Top' node +of the @file{emacs} file.@refill + +In each of the Info files, the `Up' pointer of the `Top' node refers +back to the @code{dir} file. For example, the line for the `Top' +node of the Emacs manual looks like this in Info:@refill + +@example +File: emacs Node: Top, Up: (DIR), Next: Distrib +@end example + +@noindent +In this case, the @file{dir} file name is written in upper case +letters---it can be written in either upper or lower case. This is not +true in general, it is a special case for @file{dir}. + + +@node New Info File +@subsection Listing a New Info File +@cindex Adding a new Info file +@cindex Listing a new Info file +@cindex New Info file, listing it in @file{dir} file +@cindex Info file, listing a new +@cindex @file{dir} file listing + +To add a new Info file to your system, you must write a menu entry to +add to the menu in the @file{dir} file in the @file{info} directory. +For example, if you were adding documentation for GDB, you would write +the following new entry:@refill + +@example +* GDB: (gdb). The source-level C debugger. +@end example + +@noindent +The first part of the menu entry is the menu entry name, followed by a +colon. The second part is the name of the Info file, in parentheses, +followed by a period. The third part is the description. + +The name of an Info file often has a @file{.info} extension. Thus, the +Info file for GDB might be called either @file{gdb} or @file{gdb.info}. +The Info reader programs automatically try the file name both with and +without @file{.info}@footnote{On MS-DOS/MS-Windows systems, Info will +try the @file{.inf} extension as well.}; so it is better to avoid +clutter and not to write @samp{.info} explicitly in the menu entry. For +example, the GDB menu entry should use just @samp{gdb} for the file +name, not @samp{gdb.info}. + + +@node Other Info Directories +@subsection Info Files in Other Directories +@cindex Installing Info in another directory +@cindex Info installed in another directory +@cindex Another Info directory +@cindex @file{dir} files and Info directories + +If an Info file is not in the @file{info} directory, there are three +ways to specify its location:@refill + +@enumerate +@item +Write the pathname in the @file{dir} file as the second part of the menu. + +@item +If you are using Emacs, list the name of the file in a second @file{dir} +file, in its directory; and then add the name of that directory to the +@code{Info-directory-list} variable in your personal or site +initialization file. + +This variable tells Emacs where to look for @file{dir} files (the files +must be named @file{dir}). Emacs merges the files named @file{dir} from +each of the listed directories. (In Emacs version 18, you can set the +@code{Info-directory} variable to the name of only one +directory.)@refill + +@item +Specify the Info directory name in the @code{INFOPATH} environment +variable in your @file{.profile} or @file{.cshrc} initialization file. +(Only you and others who set this environment variable will be able to +find Info files whose location is specified this way.) +@end enumerate + +For example, to reach a test file in the @file{/home/bob/info} +directory, you could add an entry like this to the menu in the +standard @file{dir} file:@refill + +@example +* Test: (/home/bob/info/info-test). Bob's own test file. +@end example + +@noindent +In this case, the absolute file name of the @file{info-test} file is +written as the second part of the menu entry.@refill + +Alternatively, you could write the following in your @file{.emacs} file: + +@vindex Info-directory-list +@example +@group +(require 'info) +(setq Info-directory-list + (cons (expand-file-name "/home/bob/info") + Info-directory-list)) +@end group +@end example + +This tells Emacs to merge the system @file{dir} file with the @file{dir} +file in @file{/home/bob/info}. Thus, Info will list the +@file{/home/bob/info/info-test} file as a menu entry in the +@file{/home/bob/info/dir} file. Emacs does the merging only when +@kbd{M-x info} is first run, so if you want to set +@code{Info-directory-list} in an Emacs session where you've already run +@code{info}, you must @code{(setq Info-dir-contents nil)} to force Emacs +to recompose the @file{dir} file. + +@vindex INFOPATH +@cindex Environment variable @code{INFOPATH} +Finally, you can tell Info where to look by setting the @code{INFOPATH} +environment variable in your shell startup file, such as @file{.cshrc}, +@file{.profile} or @file{autoexec.bat}. If you use a Bourne-compatible +shell such as @code{sh} or @code{bash} for your shell command +interpreter, you set the @code{INFOPATH} environment variable in the +@file{.profile} initialization file; but if you use @code{csh} or +@code{tcsh}, you set the variable in the @file{.cshrc} initialization +file. On MS-DOS/MS-Windows systems, you must set @code{INFOPATH} in +your @file{autoexec.bat} file or in the Registry. Each type of shell +uses a different syntax. + +@itemize @bullet +@item +In a @file{.cshrc} file, you could set the @code{INFOPATH} +variable as follows:@refill + +@smallexample +setenv INFOPATH .:~/info:/usr/local/emacs/info +@end smallexample + +@item +In a @file{.profile} file, you would achieve the same effect by +writing:@refill + +@smallexample +INFOPATH=.:$HOME/info:/usr/local/emacs/info +export INFOPATH +@end smallexample + +@item +@pindex autoexec.bat +In a @file{autoexec.bat} file, you write this command@footnote{Note the +use of @samp{;} as the directory separator, and a different syntax for +using values of other environment variables.}: + +@smallexample +set INFOPATH=.;%HOME%/info;c:/usr/local/emacs/info +@end smallexample +@end itemize + +@noindent +The @samp{.} indicates the current directory as usual. Emacs uses the +@code{INFOPATH} environment variable to initialize the value of Emacs's +own @code{Info-directory-list} variable. The stand-alone Info reader +merges any files named @file{dir} in any directory listed in the +@env{INFOPATH} variable into a single menu presented to you in the node +called @samp{(dir)Top}. + +@cindex Colon, last in @env{INFOPATH} +However you set @env{INFOPATH}, if its last character is a +colon@footnote{On MS-DOS/MS-Windows systems, use semi-colon instead.}, this +is replaced by the default (compiled-in) path. This gives you a way to +augment the default path with new directories without having to list all +the standard places. For example (using @code{sh} syntax): + +@example +INFOPATH=/local/info: +export INFOPATH +@end example + +@noindent +will search @file{/local/info} first, then the standard directories. +Leading or doubled colons are not treated specially. + +@cindex @file{dir} file, creating your own +When you create your own @file{dir} file for use with +@code{Info-directory-list} or @env{INFOPATH}, it's easiest to start by +copying an existing @file{dir} file and replace all the text after the +@samp{* Menu:} with your desired entries. That way, the punctuation and +special CTRL-_ characters that Info needs will be present. + + +@node Installing Dir Entries +@subsection Installing Info Directory Files + +When you install an Info file onto your system, you can use the program +@code{install-info} to update the Info directory file @file{dir}. +Normally the makefile for the package runs @code{install-info}, just +after copying the Info file into its proper installed location. + +@findex dircategory +@findex direntry +In order for the Info file to work with @code{install-info}, you include +the commands @code{@@dircategory} and +@code{@@direntry}@dots{}@code{@@end direntry} in the Texinfo source +file. Use @code{@@direntry} to specify the menu entries to add to the +Info directory file, and use @code{@@dircategory} to specify which part +of the Info directory to put it in. Here is how these commands are used +in this manual: + +@smallexample +@@dircategory Texinfo documentation system +@@direntry +* Texinfo: (texinfo). The GNU documentation format. +* install-info: (texinfo)Invoking install-info. @dots{} +@dots{} +@@end direntry +@end smallexample + +Here's what this produces in the Info file: + +@smallexample +INFO-DIR-SECTION Texinfo documentation system +START-INFO-DIR-ENTRY +* Texinfo: (texinfo). The GNU documentation format. +* install-info: (texinfo)Invoking install-info. @dots{} +@dots{} +END-INFO-DIR-ENTRY +@end smallexample + +@noindent +The @code{install-info} program sees these lines in the Info file, and +that is how it knows what to do. + +Always use the @code{@@direntry} and @code{@@dircategory} commands near +the beginning of the Texinfo input, before the first @code{@@node} +command. If you use them later on in the input, @code{install-info} +will not notice them. + +@code{install-info} will automatically reformat the description of the +menu entries it is adding. As a matter of convention, the description +of the main entry (above, @samp{The GNU documentation format}) should +start at column 32, starting at zero (as in +@code{what-cursor-position} in Emacs). This will make it align with +most others. Description for individual utilities best start in +column 48, where possible. For more information about formatting see +the @samp{--calign}, @samp{--align}, and @samp{--max-width} options in +@ref{Invoking install-info}. + +If you use @code{@@dircategory} more than once in the Texinfo source, +each usage specifies the `current' category; any subsequent +@code{@@direntry} commands will add to that category. + +@cindex Free Software Directory +@cindex Dir categories, choosing +@cindex Categories, choosing +When choosing a category name for the @code{@@dircategory} command, we +recommend consulting the @uref{http://www.gnu.org/directory, +Free Software Directory}. If your program is not listed there, +or listed incorrectly or incompletely, please report the situation to +the directory maintainers (@email{bug-directory@@gnu.org}) so that the +category names can be kept in sync. + +Here are a few examples (see the @file{util/dir-example} file in the +Texinfo distribution for large sample @code{dir} file): + +@display +Emacs +Localization +Printing +Software development +Software libraries +Text creation and manipulation +@end display + +@cindex Invoking nodes, including in dir file +Each `Invoking' node for every program installed should have a +corresponding @code{@@direntry}. This lets users easily find the +documentation for the different programs they can run, as with the +traditional @command{man} system. + + +@node Invoking install-info +@subsection Invoking @command{install-info} +@pindex install-info + +@code{install-info} inserts menu entries from an Info file into the +top-level @file{dir} file in the Info system (see the previous sections +for an explanation of how the @file{dir} file works). @code{install-info} +also removes menu entries from the @file{dir} file. It's most often +run as part of software installation, or when constructing a @file{dir} file +for all manuals on a system. Synopsis: + +@example +install-info [@var{option}]@dots{} [@var{info-file} [@var{dir-file}]] +@end example + +If @var{info-file} or @var{dir-file} are not specified, the options +(described below) that define them must be. There are no compile-time +defaults, and standard input is never used. @code{install-info} can +read only one Info file and write only one @file{dir} file per invocation. + +@cindex @file{dir}, created by @code{install-info} +If @var{dir-file} (however specified) does not exist, +@code{install-info} creates it if possible (with no entries). + +@cindex Compressed dir files, reading +@cindex Bzipped dir files, reading +@cindex LZMA-compressed dir files, reading +@cindex Dir files, compressed +If any input file is compressed with @code{gzip} (@pxref{Top,,,gzip, +Gzip}), @code{install-info} automatically uncompresses it +for reading. And if @var{dir-file} is compressed, @code{install-info} +also automatically leaves it compressed after writing any changes. +If @var{dir-file} itself does not exist, @code{install-info} tries to +open @file{@var{dir-file}.gz}, @file{@var{dir-file}.bz2}, and +@file{@var{dir-file}.lzma}, in that order. + +Options: + +@table @code +@item --add-once +Specifies that the entry or entries will only be put into a single section. + +@item --align=@var{column} +@opindex --align=@var{column} +Specifies the column that the second and subsequent lines of menu entry's +description will be formatted to begin at. The default for this option is +@samp{35}. It is used in conjunction with the @samp{--max-width} option. +@var{column} starts counting at 1. + +@item --append-new-sections +Instead of alphabetizing new sections, place them at the end of the DIR file. + +@item --calign=@var{column} +@opindex --calign=@var{column} +Specifies the column that the first line of menu entry's description will +be formatted to begin at. The default for this option is @samp{33}. It is +used in conjunction with the @samp{--max-width} option. +When the name of the menu entry exceeds this column, entry's description +will start on the following line. +@var{column} starts counting at 1. + +@item --debug +@opindex --debug +Report what is being done. + +@item --delete +@opindex --delete +Delete the entries in @var{info-file} from @var{dir-file}. The file +name in the entry in @var{dir-file} must be @var{info-file} (except for +an optional @samp{.info} in either one). Don't insert any new entries. +Any empty sections that result from the removal are also removed. + +@item --description=@var{text} +@opindex --description=@var{text} +Specify the explanatory portion of the menu entry. If you don't specify +a description (either via @samp{--entry}, @samp{--item} or this option), +the description is taken from the Info file itself. + +@item --dir-file=@var{name} +@opindex --dir-file=@var{name} +Specify file name of the Info directory file. This is equivalent to +using the @var{dir-file} argument. + +@item --dry-run +@opindex --dry-run +Same as @samp{--test}. + +@item --entry=@var{text} +@opindex --entry=@var{text} +Insert @var{text} as an Info directory entry; @var{text} should have the +form of an Info menu item line plus zero or more extra lines starting +with whitespace. If you specify more than one entry, they are all +added. If you don't specify any entries, they are determined from +information in the Info file itself. + +@item --help +@opindex --help +Display a usage message with basic usage and all available options, +then exit successfully. + +@item --info-file=@var{file} +@opindex --info-file=@var{file} +Specify Info file to install in the directory. This is +equivalent to using the @var{info-file} argument. + +@item --info-dir=@var{dir} +@opindex --info-dir=@var{dir} +Specify the directory where the directory file @file{dir} resides. +Equivalent to @samp{--dir-file=@var{dir}/dir}. + +@item --infodir=@var{dir} +@opindex --infodir=@var{dir} +Same as @samp{--info-dir}. + +@item --item=@var{text} +@opindex --item=@var{text} +Same as @samp{--entry=@var{text}}. An Info directory entry is actually +a menu item. + +@item --keep-old +@opindex --keep-old +Do not replace pre-existing menu entries. When @samp{--remove} is specified, +this option means that empty sections are not removed. + +@item --max-width=@var{column} +@opindex --max-width=@var{column} +Specifies the column that the menu entry's description will be word-wrapped +at. @var{column} starts counting at 1. + +@item --maxwidth=@var{column} +@opindex --maxwidth=@var{column} +Same as @samp{--max-width}. + +@item --menuentry=@var{text} +@opindex --menuentry=@var{text} +Same as @samp{--name}. + +@item --name=@var{text} +@opindex --name=@var{text} +Specify the name portion of the menu entry. If the @var{text} does +not start with an asterisk @samp{*}, it is presumed to be the text +after the @samp{*} and before the parentheses that specify the Info +file. Otherwise @var{text} is taken verbatim, and is taken as +defining the text up to and including the first period (a space is +appended if necessary). If you don't specify the name (either via +@samp{--entry}, @samp{--item} or this option), it is taken from the +Info file itself. If the Info does not contain the name, the basename +of the Info file is used. + +@item --no-indent +@opindex --no-indent +Suppress formatting of new entries into the @file{dir} file. + +@item --quiet +@opindex --quiet +@itemx --silent +@opindex --silent +Suppress warnings, etc., for silent operation. + +@item --remove +@opindex --remove +Same as @samp{--delete}. + +@item --remove-exactly +@opindex --remove-exactly +Also like @samp{--delete}, but only entries if the Info file name +matches exactly; @code{.info} and/or @code{.gz} suffixes are +@emph{not} ignored. + +@item --section=@var{sec} +@opindex --section=@var{sec} +Put this file's entries in section @var{sec} of the directory. If you +specify more than one section, all the entries are added in each of the +sections. If you don't specify any sections, they are determined from +information in the Info file itself. If the Info file doesn't specify +a section, the menu entries are put into the Miscellaneous section. + +@item --section @var{regex} @var{sec} +@opindex --section @var{regex} @var{sec} +Same as @samp{--regex=@var{regex} --section=@var{sec} --add-once}. + +@code{install-info} tries to detect when this alternate syntax is used, +but does not always guess correctly. Here is the heuristic that +@code{install-info} uses: +@enumerate +@item +If the second argument to @code{--section} starts with a hyphen, the +original syntax is presumed. +@item +If the second argument to @code{--section} is a file that can be +opened, the original syntax is presumed. +@item +Otherwise the alternate syntax is used. +@end enumerate + +When heuristic fails because your section title starts with a hyphen, or it +happens to be a filename that can be opened, the syntax should be changed +to @samp{--regex=@var{regex} --section=@var{sec} --add-once}. + + +@item --regex=@var{regex} +@opindex --regex=@var{regex} +Put this file's entries into any section that matches @var{regex}. If +more than one section matches, all of the entries are added in each of the +sections. Specify @var{regex} using basic regular expression syntax, more +or less as used with @command{grep}, for example. + +@item --test +@opindex --test +Suppress updating of the directory file. + +@item --version +@opindex --version +@cindex Version number, for install-info +Display version information and exit successfully. + +@end table + + +@node Generating HTML +@chapter Generating HTML +@cindex HTML output + +@command{makeinfo} generates Info output by default, but given the +@option{--html} option, it will generate HTML, for web browsers and +other programs. This chapter gives some details on such HTML output. + + +@command{makeinfo} can also write in XML and Docbook format, but we do +not as yet describe these further. @xref{Output Formats}, for a brief +overview of all the output formats. + +@menu +* HTML Translation:: Details of the HTML output. +* HTML Splitting:: How HTML output is split. +* HTML CSS:: Influencing HTML output with Cascading Style Sheets. +* HTML Xref:: Cross-references in HTML output. +@end menu + + +@node HTML Translation +@section HTML Translation + +@command{makeinfo} will include segments of Texinfo source between +@code{@@ifhtml} and @code{@@end ifhtml} in the HTML output (but not +any of the other conditionals, by default). Source between +@code{@@html} and @code{@@end html} is passed without change to the +output (i.e., suppressing the normal escaping of input @samp{<}, +@samp{>} and @samp{&} characters which have special significance in +HTML). @xref{Conditional Commands}. + +@opindex --footnote-style@r{, ignored in HTML output} +The @option{--footnote-style} option is currently ignored for HTML output; +footnotes are always linked to the end of the output file. + +@cindex Navigation bar, in HTML output +By default, a navigation bar is inserted at the start of each node, +analogous to Info output. The @samp{--no-headers} option suppresses +this if used with @samp{--no-split}. Header @code{<link>} elements in +split output can support info-like navigation with browsers like Lynx +and @w{Emacs W3} which implement this HTML@tie{}1.0 feature. + +@cindex HTML output, browser compatibility of +The HTML generated is mostly standard (i.e., HTML@tie{}2.0, RFC-1866). +One exception is that HTML@tie{}3.2 tables are generated from the +@code{@@multitable} command, but tagged to degrade as well as possible +in browsers without table support. The HTML@tie{}4 @samp{lang} +attribute on the @samp{<html>} attribute is also used. (Please report +output from an error-free run of @code{makeinfo} which has browser +portability problems as a bug.) + + +@node HTML Splitting +@section HTML Splitting +@cindex Split HTML output +@cindex HTML output, split + +When splitting output (which is the default), @command{makeinfo} +writes HTML output into (generally) one output file per Texinfo source +@code{@@node}. + +The output file name is the node name with special characters replaced +by @samp{-}'s, so it can work as a filename. In the unusual case of +two different nodes having the same name after this treatment, they +are written consecutively to the same file, with HTML anchors so each +can be referred to separately. If @command{makeinfo} is run on a +system which does not distinguish case in filenames, nodes which are +the same except for case will also be folded into the same output +file. + +When splitting, the HTML output files are written into a subdirectory, +with the name chosen as follows: +@enumerate +@item +@command{makeinfo} first tries the subdirectory with the base name +from @code{@@setfilename} (that is, any extension is removed). For +example, HTML output for @code{@@setfilename gcc.info} would be +written into a subdirectory named @samp{gcc}. + +@item +If that directory cannot be created for any reason, then +@command{makeinfo} tries appending @samp{.html} to the directory name. +For example, output for @code{@@setfilename texinfo} would be written +to @samp{texinfo.html}. + +@item +If the @samp{@var{name}.html} directory can't be +created either, @code{makeinfo} gives up. + +@end enumerate + +@noindent In any case, the top-level output file within the directory +is always named @samp{index.html}. + +Monolithic output (@code{--no-split}) is named according to +@code{@@setfilename} (with any @samp{.info} extension is replaced with +@samp{.html}) or @code{--output} (the argument is used literally). + + +@node HTML CSS +@section HTML CSS +@cindex HTML, and CSS +@cindex CSS, and HTML output +@cindex Cascading Style Sheets, and HTML output + +Cascading Style Sheets (CSS for short) is an Internet standard for +influencing the display of HTML documents: see +@uref{http://www.w3.org/Style/CSS/}. + +By default, @command{makeinfo} includes a few simple CSS commands to +better implement the appearance of some of the environments. Here +are two of them, as an example: + +@example +pre.display @{ font-family:inherit @} +pre.smalldisplay @{ font-family:inherit; font-size:smaller @} +@end example + +A full explanation of CSS is (far) beyond this manual; please see the +reference above. In brief, however, this specification tells the web +browser to use a `smaller' font size for @code{@@smalldisplay} text, +and to use the `inherited' font (generally a regular roman typeface) +for both @code{@@smalldisplay} and @code{@@display}. By default, the +HTML @samp{<pre>} command uses a monospaced font. + +You can influence the CSS in the HTML output with two +@command{makeinfo} options: @option{--css-include=@var{file}} and +@option{--css-ref=@var{url}}. + +The option @option{--css-ref=@var{url}} adds to each output HTML file +a @samp{<link>} tag referencing a CSS at the given @var{url}. This +allows using external style sheets. + +The option @option{--css-include=@var{file}} includes the contents +@var{file} in the HTML output, as you might expect. However, the +details are somewhat tricky, as described in the following, to provide +maximum flexibility. + +@cindex @@import specifications, in CSS files +The CSS file may begin with so-called @samp{@@import} directives, +which link to external CSS specifications for browsers to use when +interpreting the document. Again, a full description is beyond our +scope here, but we'll describe how they work syntactically, so we can +explain how @command{makeinfo} handles them. + +@cindex Comments, in CSS files +There can be more than one @samp{@@import}, but they have to come +first in the file, with only whitespace and comments interspersed, no +normal definitions. (Technical exception: an @samp{@@charset} +directive may precede the @samp{@@import}'s. This does not alter +@command{makeinfo}'s behavior, it just copies the @samp{@@charset} if +present.) Comments in CSS files are delimited by @samp{/* ... */}, as +in C. An @samp{@@import} directive must be in one of these two forms: + +@example +@@import url(http://example.org/foo.css); +@@import "http://example.net/bar.css"; +@end example + +As far as @command{makeinfo} is concerned, the crucial characters are +the @samp{@@} at the beginning and the semicolon terminating the +directive. When reading the CSS file, it simply copies any such +@samp{@@}-directive into the output, as follows: + +@itemize +@item If @var{file} contains only normal CSS declarations, it is +included after @command{makeinfo}'s default CSS, thus overriding it. + +@item If @var{file} begins with @samp{@@import} specifications (see +below), then the @samp{import}'s are included first (they have to come +first, according to the standard), and then @command{makeinfo}'s +default CSS is included. If you need to override @command{makeinfo}'s +defaults from an @samp{@@import}, you can do so with the @samp{!@: +important} CSS construct, as in: +@example +pre.smallexample @{ font-size: inherit ! important @} +@end example + +@item If @var{file} contains both @samp{@@import} and inline CSS +specifications, the @samp{@@import}'s are included first, then +@command{makeinfo}'s defaults, and lastly the inline CSS from +@var{file}. + +@item Any @@-directive other than @samp{@@import} and @samp{@@charset} +is treated as a CSS declaration, meaning @command{makeinfo} includes +its default CSS and then the rest of the file. + +@end itemize + +If the CSS file is malformed or erroneous, @command{makeinfo}'s output +is unspecified. @command{makeinfo} does not try to interpret the +meaning of the CSS file in any way; it just looks for the special +@samp{@@} and @samp{;} characters and blindly copies the text into the +output. Comments in the CSS file may or may not be included in the +output. + + +@node HTML Xref +@section HTML Cross-references +@cindex HTML cross-references +@cindex Cross-references, in HTML output + +Cross-references between Texinfo manuals in HTML format amount, in the +end, to a standard HTML @code{<a>} link, but the details are +unfortunately complex. This section describes the algorithm used in +detail, so that Texinfo can cooperate with other programs, such as +@command{texi2html}, by writing mutually compatible HTML files. + +This algorithm may or may not be used for links @emph{within} HTML +output for a Texinfo file. Since no issues of compatibility arise in +such cases, we do not need to specify this. + +We try to support references to such ``external'' manuals in both +monolithic and split forms. A @dfn{monolithic} (mono) manual is +entirely contained in one file, and a @dfn{split} manual has a file +for each node. (@xref{HTML Splitting}.) + +@cindex Dumas, Patrice +Acknowledgement: this algorithm was primarily devised by Patrice Dumas +in 2003--04. + +@menu +* Link Basics: HTML Xref Link Basics. +* Node Expansion: HTML Xref Node Name Expansion. +* Command Expansion: HTML Xref Command Expansion. +* 8-bit Expansion: HTML Xref 8-bit Character Expansion. +* Mismatch: HTML Xref Mismatch. +@end menu + + +@node HTML Xref Link Basics +@subsection HTML Cross-reference Link Basics +@cindex HTML cross-reference link basics + +For our purposes, an HTML link consists of four components: a host +name, a directory part, a file part, and a target part. We +always assume the @code{http} protocol. For example: + +@example +http://@var{host}/@var{dir}/@var{file}.html#@var{target} +@end example + +The information to construct a link comes from the node name and +manual name in the cross-reference command in the Texinfo source +(@pxref{Cross References}), and from @dfn{external information}, which +is currently simply hardwired. In the future, it may come from an +external data file. + +We now consider each part in turn. + +The @var{host} is hardwired to be the local host. This could either +be the literal string @samp{localhost}, or, according to the rules for +HTML links, the @samp{http://localhost/} could be omitted entirely. + +The @var{dir} and @var{file} parts are more complicated, and depend on +the relative split/mono nature of both the manual being processed and +the manual that the cross-reference refers to. The underlying idea is +that there is one directory for Texinfo manuals in HTML, and a given +@var{manual} is either available as a monolithic file +@file{@var{manual}.html}, or a split subdirectory +@file{@var{manual}/*.html}. Here are the cases: + +@itemize @bullet +@item +If the present manual is split, and the referent manual is also split, +the directory is @samp{../@var{referent/}} and the file is the +expanded node name (described later). + +@item +If the present manual is split, and the referent manual is mono, the +directory is @samp{../} and the file is @file{@var{referent}.html}. + +@item +If the present manual is mono, and the referent manual is split, the +directory is @file{@var{referent}/} and the file is the expanded node +name. + +@item +If the present manual is mono, and the referent manual is also mono, +the directory is @file{./} (or just the empty string), and the file is +@file{@var{referent}.html}. + +@end itemize + +One exception: the algorithm for node name expansion prefixes the +string @samp{g_t} when the node name begins with a non-letter. This +kludge (due to XHTML rules) is not necessary for filenames, and is +therefore omitted. + +Any directory part in the filename argument of the source +cross-reference command is ignored. Thus, @code{@@xref@{,,,../foo@}} +and @code{@@xref@{,,,foo@}} both use @samp{foo} as the manual name. +This is because any such attempted hardwiring of the directory is very +unlikely to be useful for both Info and HTML output. + +Finally, the @var{target} part is always the expanded node name. + +Whether the present manual is split or mono is determined by user +option; @command{makeinfo} defaults to split, with the +@option{--no-split} option overriding this. + +Whether the referent manual is split or mono is another bit of the +external information. For now, @command{makeinfo} simply assumes the +referent manual is the same as the present manual. + +There can be a mismatch between the format of the referent manual that +the generating software assumes, and the format it's actually present +in. @xref{HTML Xref Mismatch}. + + +@node HTML Xref Node Name Expansion +@subsection HTML Cross-reference Node Name Expansion +@cindex HTML cross-reference node name expansion +@cindex node name expansion, in HTML cross-references +@cindex expansion, of node names in HTML cross-references + +As mentioned in the previous section, the key part of the HTML +cross-reference algorithm is the conversion of node names in the +Texinfo source into strings suitable for XHTML identifiers and +filenames. The restrictions are similar for each: plain ASCII +letters, numbers, and the @samp{-} and @samp{_} characters are all +that can be used. (Although HTML anchors can contain most characters, +XHTML is more restrictive.) + +Cross-references in Texinfo can actually refer either to nodes or +anchors (@pxref{anchor}), but anchors are treated identically to nodes +in this context, so we'll continue to say ``node'' names for +simplicity. + +(@@-commands and 8-bit characters are not presently handled by +@command{makeinfo} for HTML cross-references. See the next section.) + +A special exception: the Top node (@pxref{The Top Node}) is always +mapped to the file @file{index.html}, to match web server software. +However, the HTML @emph{target} is @samp{Top}. Thus (in the split case): + +@example +@@xref@{Top, Introduction,, emacs, The GNU Emacs Manual@}. +@result{} <a href="emacs/index.html#Top"> +@end example + +@enumerate +@item +The standard ASCII letters (a-z and A-Z) are not modified. All other +characters are changed as specified below. + +@item +The standard ASCII numbers (0-9) are not modified except when a number +is the first character of the node name. In that case, see below. + +@item +Multiple consecutive space, tab and newline characters are transformed +into just one space. (It's not possible to have newlines in node +names with the current implementation, but we specify it anyway, just +in case.) + +@item +Leading and trailing spaces are removed. + +@item +After the above has been applied, each remaining space character is +converted into a @samp{-} character. + +@item +Other ASCII 7-bit characters are transformed into @samp{_00@var{xx}}, +where @var{xx} is the ASCII character code in (lowercase) hexadecimal. +This includes @samp{_}, which is mapped to @samp{_005f}. + +@item +If the node name does not begin with a letter, the literal string +@samp{g_t} is prefixed to the result. (Due to the rules above, that +string can never occur otherwise; it is an arbitrary choice, standing +for ``GNU Texinfo''.) This is necessary because XHTML requires that +identifiers begin with a letter. + +@end enumerate + +For example: + +@example +@@node A node --- with _'% +@result{} A-node-_002d_002d_002d-with-_005f_0027_0025 +@end example + +Notice in particular: + +@itemize @bullet +@item @samp{_} @result{} @samp{_005f} +@item @samp{-} @result{} @samp{_002d} +@item @samp{A node} @result{} @samp{A-node} +@end itemize + +On case-folding computer systems, nodes differing only by case will be +mapped to the same file. + +In particular, as mentioned above, Top always maps to the file +@file{index.html}. Thus, on a case-folding system, Top and a node +named `Index' will both be written to @file{index.html}. + +Fortunately, the targets serve to distinguish these cases, since HTML +target names are always case-sensitive, independent of operating +system. + + +@node HTML Xref Command Expansion +@subsection HTML Cross-reference Command Expansion +@cindex HTML cross-reference command expansion + +In standard Texinfo, node names may not contain @@-commands. +@command{makeinfo} has an option @option{--commands-in-node-names} +which partially supports it (@pxref{Invoking makeinfo}), but it is not +robust and not recommended. + +Thus, @command{makeinfo} does not fully implement this part of the +HTML cross-reference algorithm, but it is documented here for the sake +of completeness. + +First, comments are removed. + +Next, any @code{@@value} commands (@pxref{set value}) and macro invocations +(@pxref{Invoking Macros}) are fully expanded. + +Then, for the following commands, the command name and braces are removed, +the text of the argument is recursively transformed: +@example +@@asis @@b @@cite @@code @@command @@dfn @@dmn @@dotless +@@emph @@env @@file @@indicateurl @@kbd @@key +@@samp @@sc @@slanted @@strong @@t @@var @@w +@end example + +@noindent For @code{@@sc}, any letters are capitalized. + +The following commands are replaced by constant text, as shown. If +any of these commands have non-empty arguments, as in +@code{@@TeX@{bad@}}, it is an error, and the result is unspecified. +`(space)' means a space character, `(nothing)' means the empty string, +etc. The notation `U+@var{xxxx}' means Unicode code point @var{xxxx} +(in hex, as usual). There are further transformations of many of +these expansions for the final file or target name, such as space +characters to @samp{-}, etc., according to the other rules. + +@multitable @columnfractions .3 .5 +@item @code{@@(newline)} @tab (space) +@item @code{@@(space)} @tab (space) +@item @code{@@(tab)} @tab (space) +@item @code{@@!} @tab @samp{!} +@item @code{@@*} @tab (space) +@item @code{@@-} @tab (nothing) +@item @code{@@.} @tab @samp{.} +@item @code{@@:} @tab (nothing) +@item @code{@@?} @tab @samp{?} +@item @code{@@@@} @tab @samp{@@} +@item @code{@@@{} @tab @samp{@{} +@item @code{@@@}} @tab @samp{@}} +@item @code{@@LaTeX} @tab @samp{LaTeX} +@item @code{@@TeX} @tab @samp{TeX} +@item @code{@@arrow} @tab U+2192 +@item @code{@@bullet} @tab U+2022 +@item @code{@@comma} @tab @samp{,} +@item @code{@@copyright} @tab U+00A9 +@item @code{@@dots} @tab U+2026 +@item @code{@@enddots} @tab @samp{...} +@item @code{@@equiv} @tab U+2261 +@item @code{@@error} @tab @samp{error-->} +@item @code{@@euro} @tab U+20AC +@item @code{@@exclamdown} @tab U+00A1 +@item @code{@@expansion} @tab U+2192 +@item @code{@@geq} @tab U+2265 +@item @code{@@leq} @tab U+2264 +@item @code{@@minus} @tab U+2212 +@item @code{@@ordf} @tab U+00AA +@item @code{@@ordm} @tab U+00BA +@item @code{@@point} @tab U+2605 +@item @code{@@pounds} @tab U+00A3 +@item @code{@@print} @tab U+22A3 +@item @code{@@questiondown} @tab U+00BF +@item @code{@@registeredsymbol} @tab U+00AE +@item @code{@@result} @tab U+21D2 +@item @code{@@textdegree} @tab U+00B0 +@item @code{@@tie} @tab (space) +@end multitable + +Quotation mark commands are likewise replaced by their Unicode values +(@pxref{Inserting Quotation Marks}). + +An @code{@@acronym} or @code{@@abbr} command is replaced by the first +argument, followed by the second argument in parentheses, if present. +@xref{acronym}. + +An @code{@@email} command is replaced by the @var{text} argument if +present, else the address. @xref{email}. + +An @code{@@image} command is replaced by the filename (first) +argument. @xref{Images}. + +A @code{@@verb} command is replaced by its transformed argument. +@xref{verb}. + +Any other command is an error, and the result is unspecified. + + +@node HTML Xref 8-bit Character Expansion +@subsection HTML Cross-reference 8-bit Character Expansion +@cindex HTML cross-reference 8-bit character expansion +@cindex 8-bit characters, in HTML cross-references +@cindex Expansion of 8-bit characters in HTML cross-references +@cindex Transliteration of 8-bit characters in HTML cross-references + +Usually, characters other than plain 7-bit ASCII are transformed into +the corresponding Unicode code point(s) in Normalization Form C, which +uses precomposed characters where available. (This is the +normalization form recommended by the W3C and other bodies.) This +holds when that code point is 0xffff or less, as it almost always is. + +These will then be further transformed by the rules above into the +string @samp{_@var{xxxx}}, where @var{xxxx} is the code point in hex. + +For example, combining this rule and the previous section: + +@example +@@node @@b@{A@} @@TeX@{@} @@u@{B@} @@point@{@}@@enddots@{@} +@result{} A-TeX-B_0306-_2605_002e_002e_002e +@end example + +Notice: 1)@tie{}@code{@@enddots} expands to three periods which in +turn expands to three @samp{_002e}'s; 2)@tie{}@code{@@u@{B@}} is a `B' +with a breve accent, which does not exist as a pre-accented Unicode +character, therefore expands to @samp{B_0306} (B with combining +breve). + +When the Unicode code point is above 0xffff, the transformation is +@samp{__@var{xxxxxx}}, that is, two leading underscores followed by +six hex digits. Since Unicode has declared that their highest code +point is 0x10ffff, this is sufficient. (We felt it was better to +define this extra escape than to always use six hex digits, since the +first two would nearly always be zeros.) + +This method works fine if the node name consists mostly of ASCII +characters and contains only few 8-bit ones. If the document is +written in a language whose script is not based on the Latin alphabet +(such as, e.g. Ukrainian), it will create file names consisting +entirely of @samp{_@var{xxxx}} notations, which is inconvenient. + +To handle such cases, @command{makeinfo} offers +@option{--transliterate-file-names} command line option. This option +enables @dfn{transliteration} of node names into ASCII characters for +the purposes of file name creation and referencing. The +transliteration is based on phonetic principle, which makes the +produced file names easily readable. + +For the definition of Unicode Normalization Form C, see Unicode report +UAX#15, @uref{http://www.unicode.org/reports/tr15/}. Many related +documents and implementations are available elsewhere on the web. + + +@node HTML Xref Mismatch +@subsection HTML Cross-reference Mismatch +@cindex HTML cross-reference mismatch +@cindex Mismatched HTML cross-reference source and target + +As mentioned earlier (@pxref{HTML Xref Link Basics}), the generating +software has to guess whether a given manual being cross-referenced is +available in split or monolithic form---and, inevitably, it might +guess wrong. However, it is possible when the referent manual itself +is generated, it is possible to handle at least some mismatches. + +In the case where we assume the referent is split, but it is actually +available in mono, the only recourse would be to generate a +@file{manual/} subdirectory full of HTML files which redirect back to +the monolithic @file{manual.html}. Since this is essentially the same +as a split manual in the first place, it's not very appealing. + +On the other hand, in the case where we assume the referent is mono, +but it is actually available in split, it is possible to use +JavaScript to redirect from the putatively monolithic +@file{manual.html} to the different @file{manual/node.html} files. +Here's an example: + +@example +function redirect() @{ + switch (location.hash) @{ + case "#Node1": + location.replace("manual/Node1.html#Node1"); break; + case "#Node2" : + location.replace("manual/Node2.html#Node2"); break; + @dots{} + default:; + @} +@} +@end example + +Then, in the @code{<body>} tag of @file{manual.html}: + +@example +<body onLoad="redirect();"> +@end example + +Once again, this is something the software which generated the +@emph{referent} manual has to do in advance, it's not something the +software generating the actual cross-reference in the present manual +can control. + +Ultimately, we hope to allow for an external configuration file to +control which manuals are available from where, and how. + + +@ignore +-- not yet -- + +external information +-------------------- + +The information for the reference is searched in the file +`htmlxref.cnf' present in the following directories: +<srcdir>/.texinfo/, ~/.texinfo/, SYSCONFDIR/texinfo/, +DATADIR/texinfo/ +The first match should be used. + +The file is line-oriented, with the following format: + <manualname> <whitespace> <keyword> <whitespace> <urlprefix> +with <keyword> being "mono" or "split". Thus +texinfo split http://www.gnu.org/software/texinfo/manual/texinfo/html_node/ +texinfo mono http://www.gnu.org/software/texinfo/manual/texinfo/texinfo.html + +If the keyword is 'split', that is the target is split, the urlprefix gives +the directory and host name. +If the keyword is 'mono', that is the target is mono, the urlprefix gives +directory, host and file name. + +'#' followed by a space begins comments. '#' followed by another character +cannot begin comments as there are # in urls. + +@end ignore + + +@node Command List +@appendix @@-Command List +@cindex Alphabetical @@-command list +@cindex List of @@-commands +@cindex @@-command list +@cindex Reference to @@-commands + +Here is an alphabetical list of the @@-commands in Texinfo. Square +brackets, @t{[}@w{ }@t{]}, indicate optional arguments; an ellipsis, +@samp{@dots{}}, indicates repeated text. + +More specifics on the general syntax of different @@-commands are +given in the section below. + +@menu +* Command Syntax:: General syntax for varieties of @@-commands. +@end menu + +@sp 1 +@table @code +@item @@@var{whitespace} +An @code{@@} followed by a space, tab, or newline produces a normal, +stretchable, interword space. @xref{Multiple Spaces}. + +@item @@! +Produce an exclamation point that ends a sentence (usually after an +end-of-sentence capital letter). @xref{Ending a Sentence}. + +@item @@" +@itemx @@' +Generate an umlaut or acute accent, respectively, over the next +character, as in @"o and @'o. @xref{Inserting Accents}. + +@item @@* +Force a line break. @xref{Line Breaks}. + +@item @@,@{@var{c}@} +Generate a cedilla accent under @var{c}, as in @,{c}. @xref{Inserting +Accents}. + +@item @@- +Insert a discretionary hyphenation point. @xref{- and hyphenation}. + +@item @@. +Produce a period that ends a sentence (usually after an +end-of-sentence capital letter). @xref{Ending a Sentence}. + +@item @@/ +Produces no output, but allows a line break. @xref{Line Breaks}. + +@item @@: +Tell @TeX{} to refrain from inserting extra whitespace after an +immediately preceding period, question mark, exclamation mark, or +colon, as @TeX{} normally would. @xref{Not Ending a Sentence}. + +@item @@= +Generate a macron (bar) accent over the next character, as in @=o. +@xref{Inserting Accents}. + +@item @@? +Produce a question mark that ends a sentence (usually after an +end-of-sentence capital letter). @xref{Ending a Sentence}. + +@item @@@@ +Stands for an at sign, @samp{@@}. +@xref{Atsign Braces Comma, , Inserting @@ and @{@} and @comma{}}. + +@item @@\ +Stands for a backslash (@samp{\}) inside @code{@@math}. +@xref{math,,@code{math}}. + +@item @@^ +@itemx @@` +Generate a circumflex (hat) or grave accent, respectively, over the next +character, as in @^o and @`e. +@xref{Inserting Accents}. + +@item @@@{ +Stands for a left brace, @samp{@{}. +@xref{Atsign Braces Comma, , Inserting @@ and @{@} and @comma{}}. + +@item @@@} +Stands for a right-hand brace, @samp{@}}.@* +@xref{Atsign Braces Comma, , Inserting @@ and @{@} and @comma{}}. + +@item @@~ +Generate a tilde accent over the next character, as in @~N. +@xref{Inserting Accents}. + +@item @@AA@{@} +@itemx @@aa@{@} +Generate the uppercase and lowercase Scandinavian A-ring letters, +respectively: @AA{}, @aa{}. @xref{Inserting Accents}. + +@item @@abbr@{@var{abbreviation}@} +Indicate a general abbreviation, such as `Comput.'. @xref{abbr,, +@code{abbr}}. + +@item @@acronym@{@var{acronym}@} +Indicate an acronym in all capital letters, such as `NASA'. +@xref{acronym,, @code{acronym}}. + +@item @@AE@{@} +@itemx @@ae@{@} +Generate the uppercase and lowercase AE ligatures, respectively: +@AE{}, @ae{}. @xref{Inserting Accents}. + +@itemx @@afivepaper +Change page dimensions for the A5 paper size. @xref{A4 Paper}. + +@item @@afourlatex +@itemx @@afourpaper +@itemx @@afourwide +Change page dimensions for the A4 paper size. @xref{A4 Paper}. + +@item @@alias @var{new}=@var{existing} +Make the command @samp{@@@var{new}} a synonym for the existing command +@samp{@@@var{existing}}. @xref{alias}. + +@item @@anchor@{@var{name}@} +Define @var{name} as the current location for use as a cross-reference +target. @xref{anchor,, @code{@@anchor}}. + +@item @@appendix @var{title} +Begin an appendix. The title appears in the table of contents. In +Info, the title is underlined with asterisks. @xref{unnumbered & +appendix, , The @code{@@unnumbered} and @code{@@appendix} Commands}. + +@item @@appendixsec @var{title} +@itemx @@appendixsection @var{title} +Begin an appendix section within an appendix. The section title +appears in the table of contents. In Info, the title is underlined +with equal signs. @code{@@appendixsection} is a longer spelling of +the @code{@@appendixsec} command. @xref{unnumberedsec appendixsec +heading, , Section Commands}. + +@item @@appendixsubsec @var{title} +Begin an appendix subsection. The title appears in the table of +contents. In Info, the title is underlined with hyphens. +@xref{unnumberedsubsec appendixsubsec subheading, , Subsection +Commands}. + +@item @@appendixsubsubsec @var{title} +Begin an appendix subsubsection. The title appears in the table of +contents. In Info, the title is underlined with periods. +@xref{subsubsection,, The `subsub' Commands}. + +@item @@arrow@{@} +Generate a right arrow glyph: @samp{@arrow{}}. Used by default +for @code{@@click}. @xref{Click Sequences}. + +@item @@asis +Used following @code{@@table}, @code{@@ftable}, and @code{@@vtable} to +print the table's first column without highlighting (``as is''). +@xref{Two-column Tables}. + +@item @@author @var{author} +Typeset @var{author} flushleft and underline it. @xref{title +subtitle author, , The @code{@@title} and @code{@@author} +Commands}.@refill + +@item @@b@{@var{text}@} +Set @var{text} in a @b{bold} font. No effect in Info. @xref{Fonts}. + +@ignore +@item @@br +Force a paragraph break. If used within a line, follow @code{@@br} +with braces. @xref{br, , @code{@@br}}.@refill +@end ignore + +@item @@bullet@{@} +Generate a large round dot, @bullet{} (@samp{*} in Info). Often used +with @code{@@table}. @xref{bullet, , @code{@@bullet}}. + +@item @@bye +Stop formatting a file. The formatters do not see anything in the +input file following @code{@@bye}. @xref{Ending a File}. + +@item @@c @var{comment} +Begin a comment in Texinfo. The rest of the line does not appear in +any output. A synonym for +@code{@@comment}. @xref{Comments}. + +@item @@caption +Define the full caption for a @code{@@float}. @xref{caption shortcaption}. + +@item @@cartouche +Highlight an example or quotation by drawing a box with rounded +corners around it. Pair with @code{@@end cartouche}. No effect in +Info. @xref{cartouche, , Drawing Cartouches Around Examples}.)@refill + +@item @@center @var{line-of-text} +Center the line of text following the command. +@xref{titlefont center sp, , @code{@@center}}.@refill + +@item @@centerchap @var{line-of-text} +Like @code{@@chapter}, but centers the chapter title. @xref{chapter,, +@code{@@chapter}}. + +@item @@chapheading @var{title} +Print an unnumbered chapter-like heading, but omit from the table of +contents. In Info, the title is underlined with asterisks. +@xref{majorheading & chapheading, , @code{@@majorheading} and +@code{@@chapheading}}. + +@item @@chapter @var{title} +Begin a numbered chapter. The chapter title appears in the table of +contents. In Info, the title is underlined with asterisks. +@xref{chapter, , @code{@@chapter}}. + +@item @@cindex @var{entry} +Add @var{entry} to the index of concepts. @xref{Index Entries, , +Defining the Entries of an Index}.@refill + +@item @@cite@{@var{reference}@} +Highlight the name of a book or other reference that has no companion +Info file. @xref{cite, , @code{@@cite}}. + +@item @@click@{@} +Represent a single ``click'' in a GUI. Used within +@code{@@clicksequence}. @xref{Click Sequences}. + +@item @@clicksequence@{@var{action} @@click@{@} @var{action}@} +Represent a sequence of clicks in a GUI. @xref{Click Sequences}. + +@item @@clickstyle @@@var{cmd} +Execute @@@var{cmd} for each @code{@@click}; the default is +@code{@@arrow}. The usual following empty braces on @@@var{cmd} are +omitted. @xref{Click Sequences}. + +@item @@clear @var{flag} +Unset @var{flag}, preventing the Texinfo formatting commands from +formatting text between subsequent pairs of @code{@@ifset @var{flag}} +and @code{@@end ifset} commands, and preventing +@code{@@value@{@var{flag}@}} from expanding to the value to which +@var{flag} is set. +@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill + +@item @@code@{@var{sample-code}@} +Indicate an expression, a syntactically complete token of a program, +or a program name. Unquoted in Info output. @xref{code, , +@code{@@code}}. + +@item @@comma@{@} +Insert a comma `,' character; only needed when a literal comma would +be taken as an argument separator. @xref{Inserting a Comma}. + +@item @@command@{@var{command-name}@} +Indicate a command name, such as @command{ls}. +@xref{command,, @code{@@command}}. + +@item @@comment @var{comment} +Begin a comment in Texinfo. The rest of the line does not appear in +any output. A synonym for @code{@@c}. +@xref{Comments}. + +@item @@contents +Print a complete table of contents. Has no effect in Info, which uses +menus instead. @xref{Contents, , Generating a Table of +Contents}.@refill + +@item @@copyright@{@} +Generate the copyright symbol @copyright{}. @xref{copyright symbol,, +@code{@@copyright@{@}}}. + +@ignore +@item @@ctrl@{@var{ctrl-char}@} +Describe an ASCII control character. Insert actual control character +into Info file. @xref{ctrl, , @code{@@ctrl}}. +@end ignore + +@item @@defcodeindex @var{index-name} +Define a new index and its indexing command. Print entries in an +@code{@@code} font. @xref{New Indices, , Defining New Indices}. + +@item @@defcv @var{category} @var{class} @var{name} +@itemx @@defcvx @var{category} @var{class} @var{name} +Format a description for a variable associated with a class in +object-oriented programming. Takes three arguments: the category of +thing being defined, the class to which it belongs, and its name. +@xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. + +@item @@deffn @var{category} @var{name} @var{arguments}@dots{} +@itemx @@deffnx @var{category} @var{name} @var{arguments}@dots{} +Format a description for a function, interactive command, or similar +entity that may take arguments. @code{@@deffn} takes as arguments the +category of entity being described, the name of this particular +entity, and its arguments, if any. @xref{Definition Commands}.@refill + +@item @@defindex @var{index-name} +Define a new index and its indexing command. Print entries in a roman +font. @xref{New Indices, , Defining New Indices}.@refill + +@item @@definfoenclose @var{newcmd}, @var{before}, @var{after} +Must be used within @code{@@ifinfo}; create a new command +@code{@@@var{newcmd}} for Info that marks text by enclosing it in +strings that precede and follow the text. @xref{definfoenclose}. + +@item @@defivar @var{class} @var{instance-variable-name} +@itemx @@defivarx @var{class} @var{instance-variable-name} +Format a description for an instance variable in object-oriented +programming. The command is equivalent to @samp{@@defcv @{Instance +Variable@} @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, +Def Cmds in Detail}. + +@item @@defmac @var{macroname} @var{arguments}@dots{} +@itemx @@defmacx @var{macroname} @var{arguments}@dots{} +Format a description for a macro; equivalent to @samp{@@deffn Macro +@dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in +Detail}. + +@item @@defmethod @var{class} @var{method-name} @var{arguments}@dots{} +@itemx @@defmethodx @var{class} @var{method-name} @var{arguments}@dots{} +Format a description for a method in object-oriented programming; +equivalent to @samp{@@defop Method @dots{}}. @xref{Definition +Commands}, and @ref{deffnx,, Def Cmds in Detail}. + +@item @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{} +@itemx @@defopx @var{category} @var{class} @var{name} @var{arguments}@dots{} +Format a description for an operation in object-oriented programming. +@code{@@defop} takes as arguments the name of the category of +operation, the name of the operation's class, the name of the +operation, and its arguments, if any. @xref{Definition Commands}, and +@ref{Abstract Objects}. + +@item @@defopt @var{option-name} +@itemx @@defoptx @var{option-name} +Format a description for a user option; equivalent to @samp{@@defvr +@{User Option@} @dots{}}. @xref{Definition Commands}, and +@ref{deffnx,, Def Cmds in Detail}. + +@item @@defspec @var{special-form-name} @var{arguments}@dots{} +@itemx @@defspecx @var{special-form-name} @var{arguments}@dots{} +Format a description for a special form; equivalent to @samp{@@deffn +@{Special Form@} @dots{}}. @xref{Definition Commands}, and +@ref{deffnx,, Def Cmds in Detail}. + +@item @@deftp @var{category} @var{name-of-type} @var{attributes}@dots{} +@itemx @@deftpx @var{category} @var{name-of-type} @var{attributes}@dots{} +Format a description for a data type; its arguments are the category, +the name of the type (e.g., @samp{int}) , and then the names of +attributes of objects of that type. @xref{Definition Commands}, and +@ref{Data Types}. + +@item @@deftypecv @var{category} @var{class} @var{data-type} @var{name} +@itemx @@deftypecvx @var{category} @var{class} @var{data-type} @var{name} +Format a description for a typed class variable in object-oriented programming. +@xref{Definition Commands}, and @ref{Abstract Objects}. + +@item @@deftypefn @var{category} @var{data-type} @var{name} @var{arguments}@dots{} +@itemx @@deftypefnx @var{category} @var{data-type} @var{name} @var{arguments}@dots{} +Format a description for a function or similar entity that may take +arguments and that is typed. @code{@@deftypefn} takes as arguments the +category of entity being described, the type, the name of the +entity, and its arguments, if any. @xref{Definition Commands}, and +@ref{deffnx,, Def Cmds in Detail}. + +@item @@deftypefun @var{data-type} @var{function-name} @var{arguments}@dots{} +@itemx @@deftypefunx @var{data-type} @var{function-name} @var{arguments}@dots{} +Format a description for a function in a typed language. +The command is equivalent to @samp{@@deftypefn Function @dots{}}. +@xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. + +@item @@deftypeivar @var{class} @var{data-type} @var{variable-name} +@itemx @@deftypeivarx @var{class} @var{data-type} @var{variable-name} +Format a description for a typed instance variable in object-oriented +programming. @xref{Definition Commands}, and @ref{Abstract Objects}. + +@item @@deftypemethod @var{class} @var{data-type} @var{method-name} @var{arguments}@dots{} +@itemx @@deftypemethodx @var{class} @var{data-type} @var{method-name} @var{arguments}@dots{} +Format a description for a typed method in object-oriented programming. +@xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. + +@item @@deftypeop @var{category} @var{class} @var{data-type} @var{name} @var{arguments}@dots{} +@itemx @@deftypeopx @var{category} @var{class} @var{data-type} @var{name} @var{arguments}@dots{} +Format a description for a typed operation in object-oriented programming. +@xref{Definition Commands}, and @ref{Abstract Objects}. + +@item @@deftypevar @var{data-type} @var{variable-name} +@itemx @@deftypevarx @var{data-type} @var{variable-name} +Format a description for a variable in a typed language. The command is +equivalent to @samp{@@deftypevr Variable @dots{}}. @xref{Definition +Commands}, and @ref{deffnx,, Def Cmds in Detail}. + +@item @@deftypevr @var{category} @var{data-type} @var{name} +@itemx @@deftypevrx @var{category} @var{data-type} @var{name} +Format a description for something like a variable in a typed +language---an entity that records a value. Takes as arguments the +category of entity being described, the type, and the name of the +entity. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in +Detail}. + +@item @@defun @var{function-name} @var{arguments}@dots{} +@itemx @@defunx @var{function-name} @var{arguments}@dots{} +Format a description for a function; equivalent to +@samp{@@deffn Function @dots{}}. @xref{Definition Commands}, and +@ref{deffnx,, Def Cmds in Detail}. + +@item @@defvar @var{variable-name} +@itemx @@defvarx @var{variable-name} +Format a description for a variable; equivalent to @samp{@@defvr +Variable @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def +Cmds in Detail}. + +@item @@defvr @var{category} @var{name} +@itemx @@defvrx @var{category} @var{name} +Format a description for any kind of variable. @code{@@defvr} takes +as arguments the category of the entity and the name of the entity. +@xref{Definition Commands}, +and @ref{deffnx,, Def Cmds in Detail}. + +@item @@detailmenu +Mark the (optional) detailed node listing in a master menu. +@xref{Master Menu Parts}. + +@item @@dfn@{@var{term}@} +Indicate the introductory or defining use of a term. @xref{dfn, , +@code{@@dfn}}. + +@item @@dircategory @var{dirpart} +Specify a part of the Info directory menu where this file's entry should +go. @xref{Installing Dir Entries}. + +@item @@direntry +Begin the Info directory menu entry for this file. Pair with +@code{@@end direntry}. @xref{Installing Dir Entries}. + +@item @@display +Begin a kind of example. Like @code{@@example} (indent text, do not +fill), but do not select a new font. Pair with @code{@@end display}. +@xref{display, , @code{@@display}}. + +@item @@dmn@{@var{dimension}@} +Format a unit of measure, as in 12@dmn{pt}. Causes @TeX{} to insert a +thin space before @var{dimension}. No effect in Info. +@xref{dmn, , @code{@@dmn}}. + +@item @@docbook +Enter Docbook completely. Pair with @code{@@end docbook}. @xref{Raw +Formatter Commands}. + +@item @@documentdescription +Set the document description text, included in the HTML output. Pair +with @code{@@end documentdescription}. @xref{documentdescription,, +@code{@@documentdescription}}. + +@item @@documentencoding @var{enc} +Declare the input encoding to be @var{enc}. +@xref{documentencoding,, @code{@@documentencoding}}. + +@item @@documentlanguage @var{CC} +Declare the document language as the two-character ISO-639 abbreviation +@var{CC}. @xref{documentlanguage,, @code{@@documentlanguage}}. + +@item @@dotaccent@{@var{c}@} +Generate a dot accent over the character @var{c}, as in @dotaccent{o}. +@xref{Inserting Accents}. + +@item @@dots@{@} +Generate an ellipsis, @samp{@dots{}}. +@xref{dots, , @code{@@dots}}.@refill + +@item @@email@{@var{address}[, @var{displayed-text}]@} +Indicate an electronic mail address. +@xref{email, , @code{@@email}}. + +@item @@emph@{@var{text}@} +Emphasize @var{text}, by using @emph{italics} where possible, and +enclosing in asterisks in Info. @xref{Emphasis, , Emphasizing Text}. + +@item @@end @var{environment} +Ends @var{environment}, as in @samp{@@end example}. @xref{Formatting +Commands,,@@-commands}. + +@item @@env@{@var{environment-variable}@} +Indicate an environment variable name, such as @env{PATH}. +@xref{env,, @code{@@env}}. + +@item @@enddots@{@} +Generate an end-of-sentence ellipsis, like this: @enddots{} +@xref{dots,,@code{@@dots@{@}}}. + +@item @@enumerate [@var{number-or-letter}] +Begin a numbered list, using @code{@@item} for each entry. +Optionally, start list with @var{number-or-letter}. Pair with +@code{@@end enumerate}. @xref{enumerate, , +@code{@@enumerate}}.@refill + +@item @@equiv@{@} +Indicate to the reader the exact equivalence of two forms with a +glyph: @samp{@equiv{}}. @xref{Equivalence}.@refill + +@item @@euro@{@} +Generate the Euro currency sign. +@xref{euro,,@code{@@euro@{@}}}. + +@item @@error@{@} +Indicate to the reader with a glyph that the following text is +an error message: @samp{@error{}}. @xref{Error Glyph}.@refill + +@item @@evenfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] +@itemx @@evenheading [@var{left}] @@| [@var{center}] @@| [@var{right}] +Specify page footings resp.@: headings for even-numbered (left-hand) +pages. @xref{Custom Headings, , +How to Make Your Own Headings}.@refill + +@item @@everyfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] +@itemx @@everyheading [@var{left}] @@| [@var{center}] @@| [@var{right}] +Specify page footings resp.@: headings for every page. Not relevant to +Info. @xref{Custom Headings, , How to Make Your Own Headings}. + +@item @@example +Begin an example. Indent text, do not fill, and select fixed-width +font. Pair with @code{@@end example}. @xref{example,, @code{@@example}}. + +@item @@exampleindent @var{indent} +Indent example-like environments by @var{indent} number of spaces +(perhaps 0). @xref{exampleindent,, Paragraph Indenting}. + +@item @@exclamdown@{@} +Generate an upside-down exclamation point. @xref{Inserting Accents}. + +@item @@exdent @var{line-of-text} +Remove any indentation a line might have. @xref{exdent, , +Undoing the Indentation of a Line}.@refill + +@item @@expansion@{@} +Indicate the result of a macro expansion to the reader with a special +glyph: @samp{@expansion{}}. +@xref{expansion, , @expansion{} Indicating an Expansion}.@refill + +@item @@file@{@var{filename}@} +Highlight the name of a file, buffer, node, directory, etc. @xref{file, , +@code{@@file}}. + +@item @@finalout +Prevent @TeX{} from printing large black warning rectangles beside +over-wide lines. @xref{Overfull hboxes}.@refill + +@item @@findex @var{entry} +Add @var{entry} to the index of functions. @xref{Index Entries, , +Defining the Entries of an Index}.@refill + +@item @@float +Environment to define floating material. Pair with @code{@@end float}. +@xref{Floats}. + +@item @@flushleft +@itemx @@flushright +Do not fill text; left (right) justify every line while leaving the +right (left) end ragged. Leave font as is. Pair with @code{@@end +flushleft} (@code{@@end flushright}). @code{@@flushright} analogous. +@xref{flushleft & flushright, , @code{@@flushleft} and +@code{@@flushright}}. + +@item @@footnote@{@var{text-of-footnote}@} +Enter a footnote. Footnote text is printed at the bottom of the page +by @TeX{}; Info may format in either `End' node or `Separate' node style. +@xref{Footnotes}. + +@item @@footnotestyle @var{style} +Specify an Info file's footnote style, either @samp{end} for the end +node style or @samp{separate} for the separate node style. +@xref{Footnotes}. + +@item @@format +Begin a kind of example. Like @code{@@display}, but do not indent. +Pair with @code{@@end format}. @xref{example,, @code{@@example}}. + +@item @@ftable @var{formatting-command} +Begin a two-column table, using @code{@@item} for each entry. +Automatically enter each of the items in the first column into the +index of functions. Pair with @code{@@end ftable}. The same as +@code{@@table}, except for indexing. @xref{ftable vtable, , +@code{@@ftable} and @code{@@vtable}}.@refill + +@item @@geq@{@} +Generate a greater-than-or-equal sign, `@geq{}'. @xref{geq leq}. + +@item @@group +Disallow page breaks within following text. Pair with @code{@@end +group}. Ignored in Info. @xref{group, , @code{@@group}}. + +@item @@H@{@var{c}@} +Generate the long Hungarian umlaut accent over @var{c}, as in @H{o}. + +@item @@heading @var{title} +Print an unnumbered section-like heading, but omit from the table of +contents. In Info, the title is underlined with equal signs. +@xref{unnumberedsec appendixsec heading, , Section Commands}. + +@item @@headings @var{on-off-single-double} +Turn page headings on or off, and/or specify single-sided or double-sided +page headings for printing. @xref{headings on off, , The +@code{@@headings} Command}. + +@item @@headitem +Begin a heading row in a multitable. @xref{Multitable Rows}. + +@item @@html +Enter HTML completely. Pair with @code{@@end html}. @xref{Raw +Formatter Commands}. + +@item @@hyphenation@{@var{hy-phen-a-ted words}@} +Explicitly define hyphenation points. @xref{- and hyphenation,, +@code{@@-} and @code{@@hyphenation}}. + +@item @@i@{@var{text}@} +Set @var{text} in an @i{italic} font. No effect in Info. @xref{Fonts}. + +@item @@ifclear @var{txivar} +If the Texinfo variable @var{txivar} is not set, format the following +text. Pair with @code{@@end ifclear}. @xref{set clear value, , +@code{@@set} @code{@@clear} @code{@@value}}. + +@item @@ifdocbook +@itemx @@ifhtml +@itemx @@ifinfo +Begin text that will appear only in the given output format. +@code{@@ifinfo} output appears in both Info and (for historical +compatibility) plain text output. Pair with @code{@@end ifdocbook} +resp.@: @code{@@end ifhtml} resp.@: @code{@@end ifinfo}. +@xref{Conditionals}. + +@item @@ifnotdocbook +@itemx @@ifnothtml +@itemx @@ifnotplaintext +@itemx @@ifnottex +@itemx @@ifnotxml +Begin text to be ignored in one output format but not the others. +@code{@@ifnothtml} text is omitted from HTML output, etc. Pair with +the corresponding @code{@@end ifnot@var{format}}. +@xref{Conditionals}. + +@itemx @@ifnotinfo +Begin text to appear in output other than Info and (for historical +compatibility) plain text. Pair with @code{@@end ifnotinfo}. +@xref{Conditionals}. + +@item @@ifplaintext +Begin text that will appear only in the plain text output. +Pair with @code{@@end ifplaintext}. @xref{Conditionals}. + +@item @@ifset @var{txivar} +If the Texinfo variable @var{txivar} is set, format the following +text. Pair with @code{@@end ifset}. @xref{set clear value, , +@code{@@set} @code{@@clear} @code{@@value}}. + +@item @@iftex +Begin text to appear only in the @TeX{} output. Pair with @code{@@end +iftex}. @xref{Conditionals, , Conditionally Visible Text}.@refill + +@item @@ifxml +Begin text that will appear only in the XML output. Pair with +@code{@@end ifxml}. @xref{Conditionals}. + +@item @@ignore +Begin text that will not appear in any output. Pair with @code{@@end +ignore}. @xref{Comments, , Comments and Ignored Text}. + +@item @@image@{@var{filename}, [@var{width}], [@var{height}], [@var{alt}], [@var{ext}]@} +Include graphics image in external @var{filename} scaled to the given +@var{width} and/or @var{height}, using @var{alt} text and looking for +@samp{@var{filename}.@var{ext}} in HTML. @xref{Images}. + +@item @@include @var{filename} +Read the contents of Texinfo source file @var{filename}. @xref{Include Files}. + +@item @@indicateurl@{@var{indicateurl}@} +Indicate text that is a uniform resource locator for the World Wide +Web. @xref{indicateurl, , @code{@@indicateurl}}. + +@item @@inforef@{@var{node-name}, [@var{entry-name}], @var{info-file-name}@} +Make a cross reference to an Info file for which there is no printed +manual. @xref{inforef, , Cross references using +@code{@@inforef}}.@refill + +@item \input @var{macro-definitions-file} +Use the specified macro definitions file. This command is used only +in the first line of a Texinfo file to cause @TeX{} to make use of the +@file{texinfo} macro definitions file. The backslash in @code{\input} +is used instead of an @code{@@} because @TeX{} does not +recognize @code{@@} until after it has read the definitions file. +@xref{Texinfo File Header}. + +@item @@item +Indicate the beginning of a marked paragraph for @code{@@itemize} and +@code{@@enumerate}; indicate the beginning of the text of a first column +entry for @code{@@table}, @code{@@ftable}, and @code{@@vtable}. +@xref{Lists and Tables}. + +@item @@itemize @var{mark-generating-character-or-command} +Begin an unordered list: indented paragraphs with a mark, such as +@code{@@bullet}, inside the left margin at the beginning of each +item. Pair with @code{@@end itemize}. @xref{itemize, , +@code{@@itemize}}. + +@item @@itemx +Like @code{@@item} but do not generate extra vertical space above the +item text. Thus, when several items have the same description, use +@code{@@item} for the first and @code{@@itemx} for the others. +@xref{itemx, , @code{@@itemx}}. + +@item @@kbd@{@var{keyboard-characters}@} +Indicate characters of input to be typed by users. @xref{kbd, , +@code{@@kbd}}. + +@item @@kbdinputstyle @var{style} +Specify when @code{@@kbd} should use a font distinct from +@code{@@code}. @xref{kbd, , @code{@@kbd}}. + +@item @@key@{@var{key-name}@} +Indicate the name of a key on a keyboard. @xref{key, , @code{@@key}}. + +@item @@kindex @var{entry} +Add @var{entry} to the index of keys. +@xref{Index Entries, , Defining the Entries of an Index}.@refill + +@item @@L@{@} +@itemx @@l@{@} +Generate the uppercase and lowercase Polish suppressed-L letters, +respectively: @L{}, @l{}. + +@item @@LaTeX@{@} +Generate the @LaTeX{} logo. @xref{tex, , @TeX{} and @LaTeX{}}. + +@item @@leq@{@} +Generate a less-than-or-equal sign, `@leq{}'. @xref{geq leq}. + +@item @@lisp +Begin an example of Lisp code. Indent text, do not fill, and select +fixed-width font. Pair with @code{@@end lisp}. @xref{lisp, , @code{@@lisp}}. + +@item @@listoffloats +Produce a table-of-contents-like listing of @code{@@float}s. +@xref{listoffloats}. + +@item @@lowersections +Change subsequent chapters to sections, sections to subsections, and so +on. @xref{Raise/lower sections, , @code{@@raisesections} and +@code{@@lowersections}}.@refill + +@item @@macro @var{macroname} @{@var{params}@} +Define a new Texinfo command @code{@@@var{macroname}@{@var{params}@}}. +Pair with @code{@@end macro}. @xref{Defining Macros}. + +@item @@majorheading @var{title} +Print an unnumbered chapter-like heading, but omit from +the table of contents. This generates more vertical whitespace before +the heading than the @code{@@chapheading} command. @xref{majorheading +& chapheading, , @code{@@majorheading} and @code{@@chapheading}}. + +@item @@math@{@var{mathematical-expression}@} +Format a mathematical expression. +@xref{math, , @code{@@math}: Inserting Mathematical Expressions}. + +@item @@menu +Mark the beginning of a menu of nodes. No effect in a printed manual. +Pair with @code{@@end menu}. @xref{Menus}. + +@item @@minus@{@} +Generate a minus sign, `@minus{}'. @xref{minus, , @code{@@minus}}. + +@item @@multitable @var{column-width-spec} +Begin a multi-column table. Begin each row with @code{@@item} or +@code{@@headitem}, and separate columns with @code{@@tab}. Pair with +@code{@@end multitable}. @xref{Multitable Column Widths}. + +@item @@need @var{n} +Start a new page in a printed manual if fewer than @var{n} mils +(thousandths of an inch) remain on the current page. @xref{need, , +@code{@@need}}. + +@item @@node @var{name}, @var{next}, @var{previous}, @var{up} +Begin a new node. @xref{node, , @code{@@node}}. + +@item @@noindent +Prevent text from being indented as if it were a new paragraph. +@xref{noindent, , @code{@@noindent}}. + +@item @@novalidate +Suppress validation of node references and omit creation of auxiliary +files with @TeX{}. Use before @code{@@setfilename}. @xref{Pointer +Validation}. + +@item @@O@{@} +@itemx @@o@{@} +Generate the uppercase and lowercase O-with-slash letters, respectively: +@O{}, @o{}. + +@item @@oddfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] +@itemx @@oddheading [@var{left}] @@| [@var{center}] @@| [@var{right}] +Specify page footings resp.@: headings for odd-numbered (right-hand) +pages. @xref{Custom Headings, , +How to Make Your Own Headings}.@refill + +@item @@OE@{@} +@itemx @@oe@{@} +Generate the uppercase and lowercase OE ligatures, respectively: +@OE{}, @oe{}. @xref{Inserting Accents}. + +@item @@option@{@var{option-name}@} +Indicate a command-line option, such as @option{-l} or @option{--help}. +@xref{option,, @code{@@option}}. + +@item @@page +Start a new page in a printed manual. No effect in Info. +@xref{page, , @code{@@page}}.@refill + +@item @@pagesizes [@var{width}][, @var{height}] +Change page dimensions. @xref{pagesizes}. + +@item @@paragraphindent @var{indent} +Indent paragraphs by @var{indent} number of spaces (perhaps 0); preserve +source file indentation if @var{indent} is @code{asis}. +@xref{paragraphindent,, Paragraph Indenting}. + +@item @@pindex @var{entry} +Add @var{entry} to the index of programs. @xref{Index Entries, , Defining +the Entries of an Index}.@refill + +@item @@point@{@} +Indicate the position of point in a buffer to the reader with a +glyph: @samp{@point{}}. @xref{Point Glyph, , Indicating +Point in a Buffer}.@refill + +@item @@pounds@{@} +Generate the pounds sterling currency sign. +@xref{pounds,,@code{@@pounds@{@}}}. + +@item @@print@{@} +Indicate printed output to the reader with a glyph: +@samp{@print{}}. @xref{Print Glyph}.@refill + +@item @@printindex @var{index-name} +Generate the alphabetized index for @var{index-name} (using two columns in a printed +manual). @xref{Printing Indices & Menus}. + +@item @@pxref@{@var{node}, [@var{entry}], [@var{node-title}], [@var{info-file}], [@var{manual}]@} +Make a reference that starts with a lower case `see' in a printed +manual. Use within parentheses only. Only the first argument is +mandatory. @xref{pxref, , @code{@@pxref}}. + +@item @@questiondown@{@} +Generate an upside-down question mark. @xref{Inserting Accents}. + +@item @@quotation +Narrow the margins to indicate text that is quoted from another work. +Takes optional argument of prefix text. Pair with @code{@@end +quotation}. @xref{quotation, , @code{@@quotation}}. + +@item @@r@{@var{text}@} +Set @var{text} in the regular @r{roman} font. No effect in Info. +@xref{Fonts}. + +@item @@raisesections +Change subsequent sections to chapters, subsections to sections, and so +on. @xref{Raise/lower sections, , @code{@@raisesections} and +@code{@@lowersections}}.@refill + +@item @@ref@{@var{node}, [@var{entry}], [@var{node-title}], [@var{info-file}], [@var{manual}]@} +Make a plain reference that does not start with any special text. +Follow command with a punctuation mark. Only the first argument is +mandatory. @xref{ref, , @code{@@ref}}. + +@item @@refill +This command used to refill and indent the paragraph after all the +other processing has been done. It is no longer needed, since all +formatters now automatically refill as needed, but you may still see +it in the source to some manuals, as it does no harm. + +@item @@registeredsymbol@{@} +Generate the legal symbol @registeredsymbol{}. @xref{registered +symbol,, @code{@@registeredsymbol@{@}}}. + +@item @@result@{@} +Indicate the result of an expression to the reader with a special +glyph: @samp{@result{}}. @xref{result, , @code{@@result}}.@refill + +@item @@ringaccent@{@var{c}@} +Generate a ring accent over the next character, as in @ringaccent{o}. +@xref{Inserting Accents}. + +@item @@samp@{@var{text}@} +Indicate a literal example of a sequence of characters, in general. +Quoted in Info output. @xref{samp, , @code{@@samp}}. + +@item @@sansserif@{@var{text}@} +Set @var{text} in a @sansserif{sans serif} font if possible. No +effect in Info. @xref{Fonts}. + +@item @@sc@{@var{text}@} +Set @var{text} in a small caps font in printed output, and uppercase +in Info. @xref{Smallcaps}. + +@item @@section @var{title} +Begin a section within a chapter. The section title appears in the +table of contents. In Info, the title is underlined with equal signs. +Within @code{@@chapter} and @code{@@appendix}, the section title is +numbered; within @code{@@unnumbered}, the section is unnumbered. +@xref{section, , @code{@@section}}. + +@item @@set @var{txivar} [@var{string}] +Define the Texinfo variable @var{txivar}, optionally to the value +@var{string}. @xref{set clear value, , @code{@@set} @code{@@clear} +@code{@@value}}. + +@item @@setchapternewpage @var{on-off-odd} +Specify whether chapters start on new pages, and if so, whether on +odd-numbered (right-hand) new pages. @xref{setchapternewpage, , +@code{@@setchapternewpage}}. + +@item @@setcontentsaftertitlepage +Put the table of contents after the @samp{@@end titlepage} even if the +@code{@@contents} command is at the end. @xref{Contents}. + +@item @@setfilename @var{info-file-name} +Provide a name to be used for the output files. This command is essential +for @TeX{} formatting as well, even though it produces no output of +its own. @xref{setfilename, , @code{@@setfilename}}. + +@item @@setshortcontentsaftertitlepage +Place the short table of contents after the @samp{@@end titlepage} +command even if the @code{@@shortcontents} command is at the end. +@xref{Contents}. + +@item @@settitle @var{title} +Specify the title for page headers in a printed manual, and the +default document description for HTML @samp{<head>}. @xref{settitle,, +@code{@@settitle}}. + +@item @@shortcaption +Define the short caption for a @code{@@float}. @xref{caption shortcaption}. + +@item @@shortcontents +Print a short table of contents, with chapter-level entries only. Not +relevant to Info, which uses menus rather than tables of contents. +@xref{Contents, , Generating a Table of Contents}. + +@item @@shorttitlepage @var{title} +Generate a minimal title page. @xref{titlepage,,@code{@@titlepage}}. + +@item @@slanted@{@var{text}@} +Set @var{text} in a @slanted{slanted} font if possible. No effect +in Info. @xref{Fonts}. + +@item @@smallbook +Cause @TeX{} to produce a printed manual in a 7 by 9.25 inch format +rather than the regular 8.5 by 11 inch format. @xref{smallbook, , +Printing Small Books}. Also, see @ref{small}. + +@item @@smalldisplay +Begin a kind of example. Like @code{@@smallexample} (narrow margins, no +filling), but do not select the fixed-width font. Pair with @code{@@end +smalldisplay}. @xref{small}. + +@item @@smallexample +Begin an example. Do not fill, select fixed-width font, narrow the +margins. Where possible, print text in a smaller font than with +@code{@@example}. Pair with @code{@@end smallexample}. @xref{small}. + +@item @@smallformat +Begin a kind of example. Like @code{@@smalldisplay}, but do not narrow +the margins. Pair with @code{@@end smallformat}. @xref{small}. + +@item @@smalllisp +Begin an example of Lisp code. Same as @code{@@smallexample}. Pair +with @code{@@end smalllisp}. @xref{small}. + +@item @@sp @var{n} +Skip @var{n} blank lines. @xref{sp, , @code{@@sp}}.@refill + +@item @@ss@{@} +Generate the German sharp-S es-zet letter, @ss{}. @xref{Inserting Accents}. + +@item @@strong @{@var{text}@} +Emphasize @var{text} more strongly than @code{@@emph}, by using +@strong{boldface} where possible; enclosed in asterisks in Info. +@xref{emph & strong, , Emphasizing Text}. + +@item @@subheading @var{title} +Print an unnumbered subsection-like heading, but omit from the table +of contents of a printed manual. In Info, the title is underlined +with hyphens. @xref{unnumberedsubsec appendixsubsec subheading, , +@code{@@unnumberedsubsec} @code{@@appendixsubsec} +@code{@@subheading}}. + +@item @@subsection @var{title} +Begin a subsection within a section. The subsection title appears in +the table of contents. In Info, the title is underlined with hyphens. +Same context-dependent numbering as @code{@@section}. @xref{subsection, , +@code{@@subsection}}. + +@item @@subsubheading @var{title} +Print an unnumbered subsubsection-like heading, but omit from the +table of contents of a printed manual. In Info, the title is +underlined with periods. @xref{subsubsection, , The `subsub' +Commands}. + +@item @@subsubsection @var{title} +Begin a subsubsection within a subsection. The subsubsection title +appears in the table of contents. In Info, the title is underlined +with periods. Same context-dependent numbering as @code{@@section}. +@xref{subsubsection, , The `subsub' Commands}. + +@item @@subtitle @var{title} +In a printed manual, set a subtitle in a normal sized font flush to +the right-hand side of the page. Not relevant to Info, which does not +have title pages. @xref{title subtitle author, , @code{@@title} +@code{@@subtitle} and @code{@@author} Commands}. + +@item @@summarycontents +Print a short table of contents. Synonym for @code{@@shortcontents}. +@xref{Contents, , Generating a Table of Contents}. + +@item @@syncodeindex @var{from-index} @var{to-index} +Merge the index named in the first argument into the index named in +the second argument, formatting the entries from the first index with +@code{@@code} . @xref{Combining Indices}.@refill + +@item @@synindex @var{from-index} @var{to-index} +Merge the index named in the first argument into the index named in +the second argument. Do not change the font of @var{from-index} +entries. @xref{Combining Indices}. + +@item @@t@{@var{text}@} +Set @var{text} in a @t{fixed-width}, typewriter-like font. No effect +in Info. @xref{Fonts}. + +@item @@tab +Separate columns in a row of a multitable. @xref{Multitable Rows}. + +@item @@table @var{formatting-command} +Begin a two-column table (description list), using @code{@@item} for +each entry. Write each first column entry on the same line as +@code{@@item}. First column entries are printed in the font resulting +from @var{formatting-command}. Pair with @code{@@end table}. +@xref{Two-column Tables, , Making a Two-column Table}. Also see +@ref{ftable vtable, , @code{@@ftable} and @code{@@vtable}}, and +@ref{itemx, , @code{@@itemx}}. + +@item @@TeX@{@} +Generate the @TeX{} logo. @xref{tex, , @TeX{} and @LaTeX{}}. + +@item @@tex +Enter @TeX{} completely. Pair with @code{@@end tex}. @xref{Raw +Formatter Commands}. + +@item @@thischapter +@itemx @@thischaptername +@itemx @@thischapternum +@itemx @@thisfile +@itemx @@thispage +@itemx @@thistitle +Only allowed in a heading or footing. Stands for, respectively, the +number and name of the current chapter (in the format `Chapter 1: +Title'), the current chapter name only, the current chapter number +only, the filename, the current page number, and the title of the +document, respectively. @xref{Custom Headings, , How to Make Your Own +Headings}. + +@item @@tie@{@} +Generate a normal interword space at which a line break is not allowed. +@xref{tie,, @code{@@tie@{@}}}. + +@item @@tieaccent@{@var{cc}@} +Generate a tie-after accent over the next two characters @var{cc}, as in +`@tieaccent{oo}'. @xref{Inserting Accents}. + +@item @@tindex @var{entry} +Add @var{entry} to the index of data types. @xref{Index Entries, , +Defining the Entries of an Index}.@refill + +@item @@title @var{title} +In a printed manual, set a title flush to the left-hand side of the +page in a larger than normal font and underline it with a black rule. +Not relevant to Info, which does not have title pages. @xref{title +subtitle author, , The @code{@@title} @code{@@subtitle} and +@code{@@author} Commands}.@refill + +@item @@titlefont@{@var{text}@} +In a printed manual, print @var{text} in a larger than normal font. +@xref{titlefont center sp, , The @code{@@titlefont} @code{@@center} +and @code{@@sp} Commands}. + +@item @@titlepage +Begin the title page. Write the command on a line of its own, paired +with @code{@@end titlepage}. Nothing between @code{@@titlepage} and +@code{@@end titlepage} appears in Info. @xref{titlepage, , +@code{@@titlepage}}.@refill + +@item @@today@{@} +Insert the current date, in `1 Jan 1900' style. @xref{Custom +Headings, , How to Make Your Own Headings}.@refill + +@item @@top @var{title} +Mark the topmost @code{@@node} in the file, which must be defined on +the line immediately preceding the @code{@@top} command. The title is +formatted as a chapter-level heading. The entire top node, including +the @code{@@node} and @code{@@top} lines, are normally enclosed with +@code{@@ifnottex ... @@end ifnottex}. In @TeX{} and +@code{texinfo-format-buffer}, the @code{@@top} command is merely a +synonym for @code{@@unnumbered}. @xref{makeinfo Pointer Creation, , +Creating Pointers with @code{makeinfo}}. + +@item @@u@{@var{c}@} +@itemx @@ubaraccent@{@var{c}@} +@itemx @@udotaccent@{@var{c}@} +Generate a breve, underbar, or underdot accent, respectively, over or +under the character @var{c}, as in @u{o}, @ubaraccent{o}, +@udotaccent{o}. @xref{Inserting Accents}. + +@item @@unnumbered @var{title} +Begin a chapter that appears without chapter numbers of any kind. The +title appears in the table of contents. In Info, the title is +underlined with asterisks. @xref{unnumbered & appendix, , +@code{@@unnumbered} and @code{@@appendix}}. + +@item @@unnumberedsec @var{title} +Begin a section that appears without section numbers of any kind. The +title appears in the table of contents of a printed manual. In Info, +the title is underlined with equal signs. @xref{unnumberedsec +appendixsec heading, , Section Commands}. + +@item @@unnumberedsubsec @var{title} +Begin an unnumbered subsection. The title appears in the table of +contents. In Info, the title is underlined with hyphens. +@xref{unnumberedsubsec appendixsubsec subheading, , +@code{@@unnumberedsubsec} @code{@@appendixsubsec} +@code{@@subheading}}. + +@item @@unnumberedsubsubsec @var{title} +Begin an unnumbered subsubsection. The title appears in the table of +contents. In Info, the title is underlined with periods. +@xref{subsubsection, , The `subsub' Commands}. + +@item @@uref@{@var{url}[, @var{displayed-text}][, @var{replacement}@} +@itemx @@url@{@var{url}[, @var{displayed-text}][, @var{replacement}@} +Define a cross reference to an external uniform resource locator, +e.g., for the World Wide Web. @xref{uref, , @code{@@uref}}. + +@item @@v@{@var{c}@} +Generate check accent over the character @var{c}, as in @v{o}. +@xref{Inserting Accents}. + +@item @@value@{@var{txivar}@} +Insert the value, if any, of the Texinfo variable @var{txivar}, +previously defined by @code{@@set}. @xref{set clear value, , +@code{@@set} @code{@@clear} @code{@@value}}. + +@item @@var@{@var{metasyntactic-variable}@} +Highlight a metasyntactic variable, which is something that stands for +another piece of text. @xref{var, , Indicating Metasyntactic +Variables}. + +@item @@verb@{@var{delim} @var{literal} @var{delim}@} +Output @var{literal}, delimited by the single character @var{delim}, +exactly as is (in the fixed-width font), including any whitespace or +Texinfo special characters. @xref{verb,,@code{verb}}. + +@item @@verbatim +Output the text of the environment exactly as is (in the fixed-width +font). Pair with @code{@@end verbatim}. @xref{verbatim,,@code{verbatim}}. + +@item @@verbatiminclude @var{filename} +Output the contents of @var{filename} exactly as is (in the fixed-width font). +@xref{verbatiminclude,,@code{verbatiminclude}}. + +@item @@vindex @var{entry} +Add @var{entry} to the index of variables. @xref{Index Entries, , +Defining the Entries of an Index}.@refill + +@item @@vskip @var{amount} +In a printed manual, insert whitespace so as to push text on the +remainder of the page towards the bottom of the page. Used in +formatting the copyright page with the argument @samp{0pt plus +1filll}. (Note spelling of @samp{filll}.) @code{@@vskip} may be used +only in contexts ignored for Info. @xref{Copyright}. + +@item @@vtable @var{formatting-command} +Begin a two-column table, using @code{@@item} for each entry. +Automatically enter each of the items in the first column into the +index of variables. Pair with @code{@@end vtable}. The same as +@code{@@table}, except for indexing. @xref{ftable vtable, , +@code{@@ftable} and @code{@@vtable}}.@refill + +@item @@w@{@var{text}@} +Disallow line breaks within @var{text}. @xref{w, , @code{@@w}}. + +@item @@xml +Enter XML completely. Pair with @code{@@end xml}. @xref{Raw +Formatter Commands}. + +@item @@xref@{@var{node}, [@var{entry}], [@var{node-title}], [@var{info-file}], [@var{manual}]@} +Make a reference that starts with `See' in a printed manual. Follow +command with a punctuation mark. Only the first argument is +mandatory. @xref{xref, , @code{@@xref}}. + +@end table + + +@node Command Syntax +@section @@-Command Syntax +@cindex @@-command syntax +@cindex Syntax, of @@-commands +@cindex Command syntax + +The character @samp{@@} is used to start special Texinfo commands. +(It has the same meaning that @samp{\} has in plain @TeX{}.) Texinfo +has four types of @@-command:@refill + +@table @asis +@item 1. Non-alphabetic commands. +These commands consist of an @@ followed by a punctuation mark or +other character that is not part of the alphabet. Non-alphabetic +commands are almost always part of the text within a paragraph. The +non-alphabetic commands include @code{@@@@}, @code{@@@{}, @code{@@@}}, +@code{@@.}, @code{@@@kbd{SPACE}}, most of the accent commands, and +many more. + +@item 2. Alphabetic commands that do not require arguments. +These commands start with @@ followed by a word followed by left- and +right-hand braces. These commands insert special symbols in the +document; they do not require arguments. For example, +@code{@@dots@{@}} @result{} @samp{@dots{}}, @code{@@equiv@{@}} +@result{} @samp{@equiv{}}, @code{@@TeX@{@}} @result{} `@TeX{}', +and @code{@@bullet@{@}} @result{} @samp{@bullet{}}.@refill + +@item 3. Alphabetic commands that require arguments within braces. +These commands start with @@ followed by a letter or a word, followed by an +argument within braces. For example, the command @code{@@dfn} indicates +the introductory or defining use of a term; it is used as follows: @samp{In +Texinfo, @@@@-commands are @@dfn@{mark-up@} commands.}@refill + +@item 4. Alphabetic commands that occupy an entire line. +These commands occupy an entire line. The line starts with @@, +followed by the name of the command (a word); for example, @code{@@center} +or @code{@@cindex}. If no argument is needed, the word is followed by +the end of the line. If there is an argument, it is separated from +the command name by a space. Braces are not used.@refill +@end table + +@cindex Braces and argument syntax +Thus, the alphabetic commands fall into classes that have +different argument syntaxes. You cannot tell to which class a command +belongs by the appearance of its name, but you can tell by the +command's meaning: if the command stands for a glyph, it is in +class 2 and does not require an argument; if it makes sense to use the +command together with other text as part of a paragraph, the command +is in class 3 and must be followed by an argument in braces; +otherwise, it is in class 4 and uses the rest of the line as its +argument.@refill + +The purpose of having a different syntax for commands of classes 3 and +4 is to make Texinfo files easier to read, and also to help the GNU +Emacs paragraph and filling commands work properly. There is only one +exception to this rule: the command @code{@@refill}, which is always +used at the end of a paragraph immediately following the final period +or other punctuation character. @code{@@refill} takes no argument and +does @emph{not} require braces. @code{@@refill} never confuses the +Emacs paragraph commands because it cannot appear at the beginning of +a line. It is also no longer needed, since all formatters now refill +paragraphs automatically. + + +@node Tips +@appendix Tips and Hints + +Here are some tips for writing Texinfo documentation:@refill + +@cindex Tips +@cindex Usage tips +@cindex Hints +@itemize @bullet +@item +Write in the present tense, not in the past or the future. + +@item +Write actively! For example, write ``We recommend that @dots{}'' rather +than ``It is recommended that @dots{}''. + +@item +Use 70 or 72 as your fill column. Longer lines are hard to read. + +@item +Include a copyright notice and copying permissions. +@end itemize + +@subsubheading Index, Index, Index! + +Write many index entries, in different ways. +Readers like indices; they are helpful and convenient. + +Although it is easiest to write index entries as you write the body of +the text, some people prefer to write entries afterwards. In either +case, write an entry before the paragraph to which it applies. This +way, an index entry points to the first page of a paragraph that is +split across pages. + +Here are more hints we have found valuable: + +@itemize @bullet +@item +Write each index entry differently, so each entry refers to a different +place in the document. + +@item +Write index entries only where a topic is discussed significantly. For +example, it is not useful to index ``debugging information'' in a +chapter on reporting bugs. Someone who wants to know about debugging +information will certainly not find it in that chapter. + +@item +Consistently capitalize the first word of every concept index entry, +or else consistently use lower case. Terse entries often call for +lower case; longer entries for capitalization. Whichever case +convention you use, please use one or the other consistently! Mixing +the two styles looks bad. + +@item +Always capitalize or use upper case for those words in an index for +which this is proper, such as names of countries or acronyms. Always +use the appropriate case for case-sensitive names, such as those in C or +Lisp. + +@item +Write the indexing commands that refer to a whole section immediately +after the section command, and write the indexing commands that refer to +a paragraph before that paragraph. + +In the example that follows, a blank line comes after the index +entry for ``Leaping'': + +@example +@group +@@section The Dog and the Fox +@@cindex Jumping, in general +@@cindex Leaping + +@@cindex Dog, lazy, jumped over +@@cindex Lazy dog jumped over +@@cindex Fox, jumps over dog +@@cindex Quick fox jumps over dog +The quick brown fox jumps over the lazy dog. +@end group +@end example + +@noindent +(Note that the example shows entries for the same concept that are +written in different ways---@samp{Lazy dog}, and @samp{Dog, lazy}---so +readers can look up the concept in different ways.) +@end itemize + +@subsubheading Blank Lines + +@itemize @bullet +@item +Insert a blank line between a sectioning command and the first following +sentence or paragraph, or between the indexing commands associated with +the sectioning command and the first following sentence or paragraph, as +shown in the tip on indexing. Otherwise, a formatter may fold title and +paragraph together. + +@item +Always insert a blank line before an @code{@@table} command and after an +@code{@@end table} command; but never insert a blank line after an +@code{@@table} command or before an @code{@@end table} command. + +@need 1000 +For example, + +@example +@group +Types of fox: + +@@table @@samp +@@item Quick +Jump over lazy dogs. +@end group + +@group +@@item Brown +Also jump over lazy dogs. +@@end table + +@end group +@group +@@noindent +On the other hand, @dots{} +@end group +@end example + +Insert blank lines before and after @code{@@itemize} @dots{} @code{@@end +itemize} and @code{@@enumerate} @dots{} @code{@@end enumerate} in the +same way. +@end itemize + +@subsubheading Complete Phrases + +Complete phrases are easier to read than @dots{} + +@itemize @bullet +@item +Write entries in an itemized list as complete sentences; or at least, as +complete phrases. Incomplete expressions @dots{} awkward @dots{} like +this. + +@item +Write the prefatory sentence or phrase for a multi-item list or table as +a complete expression. Do not write ``You can set:''; instead, write +``You can set these variables:''. The former expression sounds cut off. +@end itemize + +@subsubheading Editions, Dates and Versions + +Include edition numbers, version numbers, and dates in the +@code{@@copying} text (for people reading the Texinfo file, and for the +legal copyright in the output files). Then use @code{@@insertcopying} +in the @code{@@titlepage} section (for people reading the printed +output) and the Top node (for people reading the online output). + +It is easiest to do this using @code{@@set} and @code{@@value}. +@xref{value Example, , @code{@@value} Example}, and @ref{GNU Sample Texts}. + + +@subsubheading Definition Commands + +Definition commands are @code{@@deffn}, @code{@@defun}, +@code{@@defmac}, and the like, and enable you to write descriptions in +a uniform format.@refill + +@itemize @bullet +@item +Write just one definition command for each entity you define with a +definition command. The automatic indexing feature creates an index +entry that leads the reader to the definition. + +@item +Use @code{@@table} @dots{} @code{@@end table} in an appendix that +contains a summary of functions, not @code{@@deffn} or other definition +commands. +@end itemize + +@subsubheading Capitalization + +@itemize @bullet +@item +Capitalize ``Texinfo''; it is a name. Do not write the @samp{x} or +@samp{i} in upper case. + +@item +Capitalize ``Info''; it is a name. + +@item +Write @TeX{} using the @code{@@TeX@{@}} command. Note the uppercase +@samp{T} and @samp{X}. This command causes the formatters to +typeset the name according to the wishes of Donald Knuth, who wrote +@TeX{}. +@end itemize + +@subsubheading Spaces + +Do not use spaces to format a Texinfo file, except inside of +@code{@@example} @dots{} @code{@@end example} and other literal +environments and commands. + +@need 700 +For example, @TeX{} fills the following: + +@example +@group + @@kbd@{C-x v@} + @@kbd@{M-x vc-next-action@} + Perform the next logical operation + on the version-controlled file + corresponding to the current buffer. +@end group +@end example + +@need 950 +@noindent +so it looks like this: + +@iftex +@quotation + @kbd{C-x v} + @kbd{M-x vc-next-action} + Perform the next logical operation on the version-controlled file + corresponding to the current buffer. +@end quotation +@end iftex +@ifnottex +@quotation +`C-x v' `M-x vc-next-action' Perform the next logical operation on the +version-controlled file corresponding to the current buffer. +@end quotation +@end ifnottex + +@noindent +In this case, the text should be formatted with +@code{@@table}, @code{@@item}, and @code{@@itemx}, to create a table. + + +@subsubheading @@code, @@samp, @@var, and @samp{---} + +@itemize @bullet +@item +Use @code{@@code} around Lisp symbols, including command names. +For example, + +@example +The main function is @@code@{vc-next-action@}, @dots{} +@end example + +@item +Avoid putting letters such as @samp{s} immediately after an +@samp{@@code}. Such letters look bad. + +@item +Use @code{@@var} around meta-variables. Do not write angle brackets +around them. + +@item +Use three hyphens in a row, @samp{---}, to indicate a long dash. @TeX{} +typesets these as a long dash and the Info formatters reduce three +hyphens to two. +@end itemize + +@subsubheading Periods Outside of Quotes + +Place periods and other punctuation marks @emph{outside} of quotations, +unless the punctuation is part of the quotation. This practice goes +against publishing conventions in the United States, but enables the +reader to distinguish between the contents of the quotation and the +whole passage. + +For example, you should write the following sentence with the period +outside the end quotation marks: + +@example +Evidently, @samp{au} is an abbreviation for ``author''. +@end example + +@noindent +since @samp{au} does @emph{not} serve as an abbreviation for +@samp{author.} (with a period following the word). + +@subsubheading Introducing New Terms + +@itemize @bullet +@item +Introduce new terms so that a reader who does not know them can +understand them from context; or write a definition for the term. + +For example, in the following, the terms ``check in'', ``register'' and +``delta'' are all appearing for the first time; the example sentence should be +rewritten so they are understandable. + +@quotation +The major function assists you in checking in a file to your +version control system and registering successive sets of changes to +it as deltas. +@end quotation + +@item +Use the @code{@@dfn} command around a word being introduced, to indicate +that the reader should not expect to know the meaning already, and +should expect to learn the meaning from this passage. +@end itemize + +@subsubheading @@pxref + +@c !!! maybe include this in the tips on pxref +@ignore +By the way, it is okay to use pxref with something else in front of +it within the parens, as long as the pxref is followed by the close +paren, and the material inside the parens is not part of a larger +sentence. Also, you can use xref inside parens as part of a complete +sentence so long as you terminate the cross reference with punctuation. +@end ignore +Absolutely never use @code{@@pxref} except in the special context for +which it is designed: inside parentheses, with the closing parenthesis +following immediately after the closing brace. One formatter +automatically inserts closing punctuation and the other does not. This +means that the output looks right both in printed output and in an Info +file, but only when the command is used inside parentheses. + +@subsubheading Invoking from a Shell + +You can invoke programs such as Emacs, GCC, and @code{gawk} from a +shell. The documentation for each program should contain a section that +describes this. Unfortunately, if the node names and titles for these +sections are all different, they are difficult for users to find. + +So, there is a convention to name such sections with a phrase beginning +with the word `Invoking', as in `Invoking Emacs'; this way, users can +find the section easily. + + +@subsubheading ANSI C Syntax + +When you use @code{@@example} to describe a C function's calling +conventions, use the ANSI C syntax, like this:@refill + +@example +void dld_init (char *@@var@{path@}); +@end example + +@noindent +And in the subsequent discussion, refer to the argument values by +writing the same argument names, again highlighted with +@code{@@var}.@refill + +@need 800 +Avoid the obsolete style that looks like this:@refill + +@example +#include <dld.h> + +dld_init (path) +char *path; +@end example + +Also, it is best to avoid writing @code{#include} above the +declaration just to indicate that the function is declared in a +header file. The practice may give the misimpression that the +@code{#include} belongs near the declaration of the function. Either +state explicitly which header file holds the declaration or, better +yet, name the header file used for a group of functions at the +beginning of the section that describes the functions.@refill + +@subsubheading Bad Examples + +Here are several examples of bad writing to avoid: + +In this example, say, `` @dots{} you must @code{@@dfn}@{check +in@} the new version.'' That flows better. + +@quotation +When you are done editing the file, you must perform a +@code{@@dfn}@{check in@}. +@end quotation + +In the following example, say, ``@dots{} makes a unified interface such as VC +mode possible.'' + +@quotation +SCCS, RCS and other version-control systems all perform similar +functions in broadly similar ways (it is this resemblance which makes +a unified control mode like this possible). +@end quotation + +And in this example, you should specify what `it' refers to: + +@quotation +If you are working with other people, it assists in coordinating +everyone's changes so they do not step on each other. +@end quotation + +@subsubheading And Finally @dots{} + +@itemize @bullet +@item +Pronounce @TeX{} as if the @samp{X} were a Greek `chi', as the last +sound in the name `Bach'. But pronounce Texinfo as in `speck': +``teckinfo''. + +@item +Write notes for yourself at the very end of a Texinfo file after the +@code{@@bye}. None of the formatters process text after the +@code{@@bye}; it is as if the text were within @code{@@ignore} @dots{} +@code{@@end ignore}. +@end itemize + + +@node Sample Texinfo Files +@appendix Sample Texinfo Files +@cindex Sample Texinfo files + +The first example is from the first chapter (@pxref{Short Sample}), +given here in its entirety, without commentary. The second +includes the full texts to be used in GNU manuals. + +@menu +* Short Sample Texinfo File:: +* GNU Sample Texts:: +* Verbatim Copying License:: +* All-permissive Copying License:: +@end menu + + +@node Short Sample Texinfo File +@section Short Sample +@cindex Sample Texinfo file, no comments + +Here is a complete, short sample Texinfo file, without any commentary. +You can see this file, with comments, in the first chapter. @xref{Short +Sample}. + +In a nutshell: The @command{makeinfo} program transforms a Texinfo +source file such as this into an Info file or HTML; and @TeX{} typesets +it for a printed manual. + + +@sp 1 +@example +\input texinfo @@c -*-texinfo-*- +@@c %**start of header +@@setfilename sample.info +@@settitle Sample Manual 1.0 +@@c %**end of header + +@@copying +This is a short example of a complete Texinfo file. + +Copyright @copyright{} 2005 Free Software Foundation, Inc. +@@end copying + +@@titlepage +@@title Sample Title +@@page +@@vskip 0pt plus 1filll +@@insertcopying +@@end titlepage + +@@c Output the table of the contents at the beginning. +@@contents + +@@ifnottex +@@node Top +@@top GNU Sample + +@@insertcopying +@@end ifnottex + +@@menu +* First Chapter:: The first chapter is the + only chapter in this sample. +* Index:: Complete index. +@@end menu + + +@@node First Chapter +@@chapter First Chapter + +@@cindex chapter, first + +This is the first chapter. +@@cindex index entry, another + +Here is a numbered list. + +@@enumerate +@@item +This is the first item. + +@@item +This is the second item. +@@end enumerate + + +@@node Index +@@unnumbered Index + +@@printindex cp + +@@bye +@end example + + +@node GNU Sample Texts +@section GNU Sample Texts + +@cindex GNU sample texts +@cindex Sample texts, GNU +@cindex Full texts, GNU + +Following is a sample Texinfo document with the full texts that should +be used in GNU manuals. + +As well as the legal texts, it also serves as a practical example of how +many elements in a GNU system can affect the manual. If you're not +familiar with all these different elements, don't worry. They're not +required and a perfectly good manual can be written without them. +They're included here nonetheless because many manuals do (or could) +benefit from them. + +@xref{Short Sample}, for a minimal example of a Texinfo file. +@xref{Beginning a File}, for a full explanation of that minimal +example. + +Here are some notes on the example: + +@itemize @bullet +@item +@cindex $Id +@cindex CVS $Id +@cindex RCS $Id +@cindex Documentation identification +@cindex Identification of documentation +The @samp{$Id:} comment is for the CVS (@pxref{Top,, Overview, cvs, +Concurrent Versions System}) or RCS +(@url{http://www.gnu.org/software/rcs}) version control systems, which +expand it into a string such as: +@example +$Id: texinfo.txi,v 1.225 2008/09/07 22:47:46 karl Exp $ +@end example +(This is useful in all sources that use version control, not just manuals.) +You may wish to include the @samp{$Id:} comment in the @code{@@copying} +text, if you want a completely unambiguous reference to the +documentation version. + +If you want to literally write @t{@w{$}Id$}, use @code{@@w}: +@code{@@w@{$@}Id$}. Unfortunately, this technique does not currently +work in plain text output, since it's not clear what should be done. +We hope to find a solution in a future release. + +@item +@pindex automake@r{, and version info} +@vindex UPDATED @r{Automake variable} +@vindex VERSION @r{Automake variable} +@pindex time-stamp.el +The @file{version.texi} in the @code{@@include} command is maintained +automatically by Automake (@pxref{Top,, Introduction, automake, GNU +Automake}). It sets the @samp{VERSION} and @samp{UPDATED} values used +elsewhere. If your distribution doesn't use Automake, but you do use +Emacs, you may find the time-stamp.el package helpful (@pxref{Time +Stamps,,,emacs,The GNU Emacs Manual}). + +@item +The @code{@@syncodeindex} command reflects the recommendation to use +only one index where possible, to make it easier for readers to look up +index entries. + +@item +The @code{@@dircategory} is for constructing the Info directory. +@xref{Installing Dir Entries}, which includes a variety of recommended +category names. + +@item +The `Invoking' node is a GNU standard to help users find the basic +information about command-line usage of a given program. @xref{Manual +Structure Details,,,standards, GNU Coding Standards}. + +@item +@cindex GNU Free Documentation License, including entire +@cindex Free Documentation License, including entire +It is best to include the entire GNU Free Documentation License in a GNU +manual, unless the manual is only a few pages long. Of course this +sample is even shorter than that, but it includes the FDL anyway in +order to show one conventional way to do so. The @file{fdl.texi} file +is available on the GNU machines and in the Texinfo and other GNU +source distributions. + +The FDL provides for omitting itself under certain conditions, but in +that case the sample texts given here have to be modified. @xref{GNU +Free Documentation License}. + +@item +If the FSF is not the copyright holder, then use the appropriate name. + +@item +If your manual is not published on paper by the FSF, then omit the +last sentence in the Back-Cover Text that talks about copies from GNU +Press. + +@item +If your manual has Invariant Sections (again, see the license itself +for details), then change the text here accordingly. + +@item +For documents that express your personal views, feelings or experiences, +it is more appropriate to use a license permitting only verbatim +copying, rather than the FDL. @xref{Verbatim Copying License}. + +@end itemize + +Here is the sample document: + +@verbatim +\input texinfo @c -*-texinfo-*- +@comment $Id: texinfo.txi,v 1.225 2008/09/07 22:47:46 karl Exp $ +@comment %**start of header +@setfilename sample.info +@include version.texi +@settitle GNU Sample @value{VERSION} +@syncodeindex pg cp +@comment %**end of header +@copying +This manual is for GNU Sample (version @value{VERSION}, @value{UPDATED}), +which is an example in the Texinfo documentation. + +Copyright @copyright{} 2007 Free Software Foundation, Inc. + +@quotation +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no +Invariant Sections, with the Front-Cover Texts being ``A GNU Manual,'' +and with the Back-Cover Texts as in (a) below. A copy of the +license is included in the section entitled ``GNU Free Documentation +License.'' + +(a) The FSF's Back-Cover Text is: ``You have the freedom to +copy and modify this GNU manual. Buying copies from the FSF +supports it in developing GNU and promoting software freedom.'' +@end quotation +@end copying + +@dircategory Texinfo documentation system +@direntry +* sample: (sample)Invoking sample. +@end direntry + +@titlepage +@title GNU Sample +@subtitle for version @value{VERSION}, @value{UPDATED} +@author A.U. Thor (@email{bug-texinfo@@gnu.org}) +@page +@vskip 0pt plus 1filll +@insertcopying +@end titlepage + +@contents + +@ifnottex +@node Top +@top GNU Sample + +This manual is for GNU Sample (version @value{VERSION}, @value{UPDATED}). +@end ifnottex + +@menu +* Invoking sample:: +* Copying This Manual:: +* Index:: +@end menu + + +@node Invoking sample +@chapter Invoking sample + +@pindex sample +@cindex invoking @command{sample} + +This is a sample manual. There is no sample program to +invoke, but if there was, you could see its basic usage +and command line options here. + + +@node GNU Free Documentation License +@appendix GNU Free Documentation License + +@include fdl.texi + + +@node Index +@unnumbered Index + +@printindex cp + +@bye +@end verbatim + + +@node Verbatim Copying License +@section Verbatim Copying License + +@cindex Verbatim copying license +@cindex License for verbatim copying + +For software manuals and other documentation, it is important to use a +license permitting free redistribution and updating, so that when a free +program is changed, the documentation can be updated as well. + +On the other hand, for documents that express your personal views, +feelings or experiences, it is more appropriate to use a license +permitting only verbatim copying. + +Here is sample text for such a license permitting verbatim copying only. +This is just the license text itself. For a complete sample document, +see the previous sections. + +@verbatim +@copying +This document is a sample for allowing verbatim copying only. + +Copyright @copyright{} 2005 Free Software Foundation, Inc. + +@quotation +Permission is granted to make and distribute verbatim copies +of this entire document without royalty provided the +copyright notice and this permission notice are preserved. +@end quotation +@end copying +@end verbatim + + +@node All-permissive Copying License +@section All-permissive Copying License + +@cindex All-permissive copying license +@cindex License for all-permissive copying + +For software manuals and other documentation, it is important to use a +license permitting free redistribution and updating, so that when a free +program is changed, the documentation can be updated as well. + +On the other hand, for small supporting files, short manuals (under 300 +lines long) and rough documentation (README files, INSTALL files, etc.), +the full FDL would be overkill. They can use a simple all-permissive +license. + +Here is sample text for such an all-permissive license. This is just +the license text itself. For a complete sample document, see the +previous sections. + +@example +Copyright @copyright{} 2005 Free Software Foundation, Inc. + +Copying and distribution of this file, with or without modification, +are permitted in any medium without royalty provided the copyright +notice and this notice are preserved. +@end example + + +@node Include Files +@appendix Include Files +@cindex Include files + +When @TeX{} or an Info formatting command sees an @code{@@include} +command in a Texinfo file, it processes the contents of the file named +by the command and incorporates them into the DVI or Info file being +created. Index entries from the included file are incorporated into +the indices of the output file. + +Include files let you keep a single large document as a collection of +conveniently small parts. + +@menu +* Using Include Files:: How to use the @code{@@include} command. +* texinfo-multiple-files-update:: How to create and update nodes and + menus when using included files. +* Include Files Requirements:: @code{texinfo-multiple-files-update} needs. +* Sample Include File:: A sample outer file with included files + within it; and a sample included file. +* Include Files Evolution:: How use of the @code{@@include} command + has changed over time. +@end menu + +@node Using Include Files +@section How to Use Include Files +@findex include + +To include another file within a Texinfo file, write the +@code{@@include} command at the beginning of a line and follow it on +the same line by the name of a file to be included. For example: + +@example +@@include buffers.texi +@end example + +The name of the file is taken literally, with a single exception: +@code{@@value@{@var{var}@}} references are expanded. This makes it +possible to reliably include files in other directories in a +distribution. @xref{verbatiminclude,,@code{@@verbatiminclude}}, for +an example. + +An included file should simply be a segment of text that you expect to +be included as is into the overall or @dfn{outer} Texinfo file; it +should not contain the standard beginning and end parts of a Texinfo +file. In particular, you should not start an included file with a +line saying @samp{\input texinfo}; if you do, that phrase is inserted +into the output file as is. Likewise, you should not end an included +file with an @code{@@bye} command; nothing after @code{@@bye} is +formatted. + +In the past, you were required to write an @code{@@setfilename} line at the +beginning of an included file, but no longer. Now, it does not matter +whether you write such a line. If an @code{@@setfilename} line exists +in an included file, it is ignored.@refill + +Conventionally, an included file begins with an @code{@@node} line that +is followed by an @code{@@chapter} line. Each included file is one +chapter. This makes it easy to use the regular node and menu creating +and updating commands to create the node pointers and menus within the +included file. However, the simple Emacs node and menu creating and +updating commands do not work with multiple Texinfo files. Thus you +cannot use these commands to fill in the `Next', `Previous', and `Up' +pointers of the @code{@@node} line that begins the included file. Also, +you cannot use the regular commands to create a master menu for the +whole file. Either you must insert the menus and the `Next', +`Previous', and `Up' pointers by hand, or you must use the GNU Emacs +Texinfo mode command, @code{texinfo-multiple-files-update}, that is +designed for @code{@@include} files.@refill + +When an included file does not have any node lines in it, the +multiple files update command does not try to create a menu entry +for it. Consequently, you can include any file, such as a +version or an update file without node lines, not just files that +are chapters. Small includable files like this are created by +Automake (@pxref{GNU Sample Texts}). + + +@node texinfo-multiple-files-update +@section @code{texinfo-multiple-files-update} +@findex texinfo-multiple-files-update + +GNU Emacs Texinfo mode provides the @code{texinfo-multiple-files-update} +command. This command creates or updates `Next', `Previous', and `Up' +pointers of included files as well as those in the outer or overall +Texinfo file, and it creates or updates a main menu in the outer file. +Depending whether you call it with optional arguments, the command +updates only the pointers in the first @code{@@node} line of the +included files or all of them:@refill + +@table @kbd +@item M-x texinfo-multiple-files-update +Called without any arguments:@refill + +@itemize @minus +@item +Create or update the `Next', `Previous', and `Up' pointers of the +first @code{@@node} line in each file included in an outer or overall +Texinfo file.@refill + +@item +Create or update the `Top' level node pointers of the outer or +overall file.@refill + +@item +Create or update a main menu in the outer file.@refill +@end itemize + +@item C-u M-x texinfo-multiple-files-update +Called with @kbd{C-u} as a prefix argument: + +@itemize @minus{} +@item +Create or update pointers in the first @code{@@node} line in each +included file. + +@item +Create or update the `Top' level node pointers of the outer file. + +@item +Create and insert a master menu in the outer file. The master menu +is made from all the menus in all the included files.@refill +@end itemize + +@item C-u 8 M-x texinfo-multiple-files-update +Called with a numeric prefix argument, such as @kbd{C-u 8}: + +@itemize @minus +@item +Create or update @strong{all} the `Next', `Previous', and `Up' pointers +of all the included files.@refill + +@item +Create or update @strong{all} the menus of all the included +files.@refill + +@item +Create or update the `Top' level node pointers of the outer or +overall file.@refill + +@item +And then create a master menu in the outer file. This is similar to +invoking @code{texinfo-master-menu} with an argument when you are +working with just one file.@refill +@end itemize +@end table + +Note the use of the prefix argument in interactive use: with a regular +prefix argument, just @w{@kbd{C-u}}, the +@code{texinfo-multiple-files-update} command inserts a master menu; +with a numeric prefix argument, such as @kbd{C-u 8}, the command +updates @strong{every} pointer and menu in @strong{all} the files and then inserts a +master menu.@refill + + +@node Include Files Requirements +@section Include Files Requirements +@cindex Include files requirements +@cindex Requirements for include files + +If you plan to use the @code{texinfo-multiple-files-update} command, +the outer Texinfo file that lists included files within it should +contain nothing but the beginning and end parts of a Texinfo file, and +a number of @code{@@include} commands listing the included files. It +should not even include indices, which should be listed in an included +file of their own.@refill + +Moreover, each of the included files must contain exactly one highest +level node (conventionally, @code{@@chapter} or equivalent), +and this node must be the first node in the included file. +Furthermore, each of these highest level nodes in each included file +must be at the same hierarchical level in the file structure. +Usually, each is an @code{@@chapter}, an @code{@@appendix}, or an +@code{@@unnumbered} node. Thus, normally, each included file contains +one, and only one, chapter or equivalent-level node.@refill + +The outer file should contain only @emph{one} node, the `Top' node. It +should @emph{not} contain any nodes besides the single `Top' node. The +@code{texinfo-multiple-files-update} command will not process +them.@refill + + +@node Sample Include File +@section Sample File with @code{@@include} +@cindex Sample @code{@@include} file +@cindex Include file sample +@cindex @code{@@include} file sample + +Here is an example of an outer Texinfo file with @code{@@include} files +within it before running @code{texinfo-multiple-files-update}, which +would insert a main or master menu: + +@example +@group +\input texinfo @@c -*-texinfo-*- +@c %**start of header +@@setfilename include-example.info +@@settitle Include Example +@c %**end of header +@end group + +... @xref{Sample Texinfo Files}, for +examples of the rest of the frontmatter ... + +@group +@@ifnottex +@@node Top +@@top Include Example +@@end ifnottex +@end group + +@group +@@include foo.texinfo +@@include bar.texinfo +@@include concept-index.texinfo +@@bye +@end group +@end example + +An included file, such as @file{foo.texinfo}, might look like this: + +@example +@group +@@node First +@@chapter First Chapter + +Contents of first chapter @dots{} +@end group +@end example + +The full contents of @file{concept-index.texinfo} might be as simple as this: + +@example +@group +@@node Concept Index +@@unnumbered Concept Index + +@@printindex cp +@end group +@end example + +The outer Texinfo source file for @cite{The GNU Emacs Lisp Reference +Manual} is named @file{elisp.texi}. This outer file contains a master +menu with 417 entries and a list of 41 @code{@@include} +files. + + +@node Include Files Evolution +@section Evolution of Include Files + +When Info was first created, it was customary to create many small +Info files on one subject. Each Info file was formatted from its own +Texinfo source file. This custom meant that Emacs did not need to +make a large buffer to hold the whole of a large Info file when +someone wanted information; instead, Emacs allocated just enough +memory for the small Info file that contained the particular +information sought. This way, Emacs could avoid wasting memory.@refill + +References from one file to another were made by referring to the file +name as well as the node name. (@xref{Other Info Files, , Referring to +Other Info Files}. Also, see @ref{Four and Five Arguments, , +@code{@@xref} with Four and Five Arguments}.)@refill + +Include files were designed primarily as a way to create a single, +large printed manual out of several smaller Info files. In a printed +manual, all the references were within the same document, so @TeX{} +could automatically determine the references' page numbers. The Info +formatting commands used include files only for creating joint +indices; each of the individual Texinfo files had to be formatted for +Info individually. (Each, therefore, required its own +@code{@@setfilename} line.)@refill + +However, because large Info files are now split automatically, it is +no longer necessary to keep them small.@refill + +Nowadays, multiple Texinfo files are used mostly for large documents, +such as @cite{The GNU Emacs Lisp Reference Manual}, and for projects +in which several different people write different sections of a +document simultaneously.@refill + +In addition, the Info formatting commands have been extended to work +with the @code{@@include} command so as to create a single large Info +file that is split into smaller files if necessary. This means that +you can write menus and cross references without naming the different +Texinfo files.@refill + + +@node Headings +@appendix Page Headings +@cindex Headings +@cindex Footings +@cindex Page numbering +@cindex Page headings +@cindex Formatting headings and footings + +Most printed manuals contain headings along the top of every page +except the title and copyright pages. Some manuals also contain +footings. (Headings and footings have no meaning to Info, which is +not paginated.)@refill + +@menu +* Headings Introduced:: Conventions for using page headings. +* Heading Format:: Standard page heading formats. +* Heading Choice:: How to specify the type of page heading. +* Custom Headings:: How to create your own headings and footings. +@end menu + +@node Headings Introduced +@section Headings Introduced + +Texinfo provides standard page heading formats for manuals that are +printed on one side of each sheet of paper and for manuals that are +printed on both sides of the paper. Typically, you will use these +formats, but you can specify your own format if you wish.@refill + +In addition, you can specify whether chapters should begin on a new +page, or merely continue the same page as the previous chapter; and if +chapters begin on new pages, you can specify whether they must be +odd-numbered pages.@refill + +By convention, a book is printed on both sides of each sheet of paper. +When you open a book, the right-hand page is odd-numbered, and +chapters begin on right-hand pages---a preceding left-hand page is +left blank if necessary. Reports, however, are often printed on just +one side of paper, and chapters begin on a fresh page immediately +following the end of the preceding chapter. In short or informal +reports, chapters often do not begin on a new page at all, but are +separated from the preceding text by a small amount of whitespace.@refill + +The @code{@@setchapternewpage} command controls whether chapters begin +on new pages, and whether one of the standard heading formats is used. +In addition, Texinfo has several heading and footing commands that you +can use to generate your own heading and footing formats.@refill + +In Texinfo, headings and footings are single lines at the tops and +bottoms of pages; you cannot create multiline headings or footings. +Each header or footer line is divided into three parts: a left part, a +middle part, and a right part. Any part, or a whole line, may be left +blank. Text for the left part of a header or footer line is set +flushleft; text for the middle part is centered; and, text for the +right part is set flushright.@refill + +@node Heading Format +@comment node-name, next, previous, up +@section Standard Heading Formats + +Texinfo provides two standard heading formats, one for manuals printed +on one side of each sheet of paper, and the other for manuals printed +on both sides of the paper. + +By default, nothing is specified for the footing of a Texinfo file, +so the footing remains blank.@refill + +The standard format for single-sided printing consists of a header +line in which the left-hand part contains the name of the chapter, the +central part is blank, and the right-hand part contains the page +number.@refill + +@need 950 +A single-sided page looks like this: + +@example +@group + _______________________ + | | + | chapter page number | + | | + | Start of text ... | + | ... | + | | +@end group +@end example + +The standard format for two-sided printing depends on whether the page +number is even or odd. By convention, even-numbered pages are on the +left- and odd-numbered pages are on the right. (@TeX{} will adjust the +widths of the left- and right-hand margins. Usually, widths are +correct, but during double-sided printing, it is wise to check that +pages will bind properly---sometimes a printer will produce output in +which the even-numbered pages have a larger right-hand margin than the +odd-numbered pages.)@refill + +In the standard double-sided format, the left part of the left-hand +(even-numbered) page contains the page number, the central part is +blank, and the right part contains the title (specified by the +@code{@@settitle} command). The left part of the right-hand +(odd-numbered) page contains the name of the chapter, the central part +is blank, and the right part contains the page number.@refill + +@need 750 +Two pages, side by side as in an open book, look like this:@refill + +@example +@group + _______________________ _______________________ + | | | | + | page number title | | chapter page number | + | | | | + | Start of text ... | | More text ... | + | ... | | ... | + | | | | +@end group +@end example + +@noindent +The chapter name is preceded by the word ``Chapter'', the chapter number +and a colon. This makes it easier to keep track of where you are in the +manual.@refill + +@node Heading Choice +@comment node-name, next, previous, up +@section Specifying the Type of Heading + +@TeX{} does not begin to generate page headings for a standard Texinfo +file until it reaches the @code{@@end titlepage} command. Thus, the +title and copyright pages are not numbered. The @code{@@end +titlepage} command causes @TeX{} to begin to generate page headings +according to a standard format specified by the +@code{@@setchapternewpage} command that precedes the +@code{@@titlepage} section.@refill + +@need 1000 +There are four possibilities:@refill + +@table @asis +@item No @code{@@setchapternewpage} command +Cause @TeX{} to specify the single-sided heading format, with chapters +on new pages. This is the same as @code{@@setchapternewpage on}.@refill + +@item @code{@@setchapternewpage on} +Specify the single-sided heading format, with chapters on new pages.@refill + +@item @code{@@setchapternewpage off} +Cause @TeX{} to start a new chapter on the same page as the last page of +the preceding chapter, after skipping some vertical whitespace. Also +cause @TeX{} to typeset for single-sided printing. (You can override +the headers format with the @code{@@headings double} command; see +@ref{headings on off, , The @code{@@headings} Command}.)@refill + +@item @code{@@setchapternewpage odd} +Specify the double-sided heading format, with chapters on new pages.@refill +@end table + +@noindent +Texinfo lacks an @code{@@setchapternewpage even} command.@refill + +@node Custom Headings +@comment node-name, next, previous, up +@section How to Make Your Own Headings + +You can use the standard headings provided with Texinfo or specify +your own. By default, Texinfo has no footers, so if you specify them, +the available page size for the main text will be slightly reduced. + +Texinfo provides six commands for specifying headings and +footings: +@itemize @bullet +@item +@code{@@everyheading} @code{@@everyfooting} generate page headers and +footers that are the same for both even- and odd-numbered pages. +@item +@code{@@evenheading} and @code{@@evenfooting} command generate headers +and footers for even-numbered (left-hand) pages. +@item +@code{@@oddheading} and @code{@@oddfooting} generate headers and footers +for odd-numbered (right-hand) pages. +@end itemize + +Write custom heading specifications in the Texinfo file immediately +after the @code{@@end titlepage} command. +You must cancel the predefined heading commands with the +@code{@@headings off} command before defining your own +specifications. + +@need 1000 +Here is how to tell @TeX{} to place the chapter name at the left, the +page number in the center, and the date at the right of every header +for both even- and odd-numbered pages: + +@example +@group +@@headings off +@@everyheading @@thischapter @@| @@thispage @@| @@today@{@} +@end group +@end example + +@noindent +You need to divide the left part from the central part and the central +part from the right part by inserting @samp{@@|} between parts. +Otherwise, the specification command will not be able to tell where +the text for one part ends and the next part begins. + +Each part can contain text or @@-commands. The text +is printed as if the part were within an ordinary paragraph in the +body of the page. The @@-commands replace +themselves with the page number, date, chapter name, or +whatever. + +@need 950 +Here are the six heading and footing commands: + +@table @code +@item @@everyheading @var{left} @@| @var{center} @@| @var{right} +@itemx @@everyfooting @var{left} @@| @var{center} @@| @var{right} +@findex everyheading +@findex everyfooting +The `every' commands specify the format for both even- and odd-numbered +pages. These commands are for documents that are printed on one side +of each sheet of paper, or for documents in which you want symmetrical +headers or footers. + +@item @@evenheading @var{left} @@| @var{center} @@| @var{right} +@itemx @@oddheading @var{left} @@| @var{center} @@| @var{right} +@itemx @@evenfooting @var{left} @@| @var{center} @@| @var{right} +@itemx @@oddfooting @var{left} @@| @var{center} @@| @var{right} +@findex evenheading +@findex evenfooting +@findex oddheading +@findex oddfooting +The `even' and `odd' commands specify the format for even-numbered +pages and odd-numbered pages. These commands are for books and +manuals that are printed on both sides of each sheet of paper. +@end table + +Use the @samp{@@this@dots{}} series of @@-commands to +provide the names of chapters +and sections and the page number. You can use the +@samp{@@this@dots{}} commands in the left, center, or right portions +of headers and footers, or anywhere else in a Texinfo file so long as +they are between @code{@@iftex} and @code{@@end iftex} commands. + +@need 1000 +Here are the @samp{@@this@dots{}} commands: + +@table @code +@item @@thispage +@findex thispage +Expands to the current page number. + +@item @@thissectionname +@findex thissectionname +Expands to the name of the current section. + +@item @@thissectionnum +@findex thissectionnum +Expands to the number of the current section. + +@item @@thissection +@findex thissection +Expands to the number and name of the current section, in the format +`Section 1: Title'. + +@item @@thischaptername +@findex thischaptername +Expands to the name of the current chapter. + +@item @@thischapternum +@findex thischapternum +Expands to the number of the current chapter, or letter of the current +appendix. + +@item @@thischapter +@findex thischapter +Expands to the number and name of the current +chapter, in the format `Chapter 1: Title'. + +@item @@thistitle +@findex thistitle +Expands to the name of the document, as specified by the +@code{@@settitle} command. + +@item @@thisfile +@findex thisfile +For @code{@@include} files only: expands to the name of the current +@code{@@include} file. If the current Texinfo source file is not an +@code{@@include} file, this command has no effect. This command does +@emph{not} provide the name of the current Texinfo source file unless +it is an @code{@@include} file. (@xref{Include Files}, for more +information about @code{@@include} files.) +@end table + +@noindent +You can also use the @code{@@today@{@}} command, which expands to the +current date, in `1 Jan 1900' format. +@findex today + +Other @@-commands and text are printed in a header or footer just as +if they were in the body of a page. It is useful to incorporate text, +particularly when you are writing drafts: + +@example +@group +@@headings off +@@everyheading @@emph@{Draft!@} @@| @@thispage @@| @@thischapter +@@everyfooting @@| @@| Version: 0.27: @@today@{@} +@end group +@end example + +Beware of overlong titles: they may overlap another part of the +header or footer and blot it out. + +If you have very short chapters and/or sections, several of them can +appear on a single page. You can specify which chapters and sections +you want @code{@@thischapter}, @code{@@thissection} and other such +macros to refer to on such pages as follows: + +@table @code +@item @@everyheadingmarks @var{ref} +@itemx @@everyfootingmarks @var{ref} +@findex everyheadingmarks +@findex everyfootingmarks +The @var{ref} argument can be either @code{top} (the @code{@@this...} +commands will refer to the chapter/section at the top of a page) or +@code{bottom} (the commands will reflect the situation at the bottom +of a page). These @samp{@@every...} commands specify what to do on +both even- and odd-numbered pages. + +@item @@evenheadingmarks @var{ref} +@itemx @@oddheadingmarks @var{ref} +@itemx @@evenfootingmarks @var{ref} +@itemx @@oddfootingmarks @var{ref} +@findex evenheadingmarks +@findex oddheadingmarks +@findex evenfootingmarks +@findex oddfootingmarks +These @samp{@@even...} and @samp{@@odd...} commands specify what to do +on only even- or odd-numbered pages, respectively. The @var{ref} +argument is the same as with the @samp{@@every...} commands. +@end table + +Write these commands immediately after the @code{@@...contents} +commands, or after the @code{@@end titlepage} command if you don't +have a table of contents or if it is printed at the end of your +manual. + +By default the @code{@@this...} commands reflect the situation at the +bottom of a page both in headings and in footings. + + +@node Catching Mistakes +@appendix Formatting Mistakes +@cindex Structure, catching mistakes in +@cindex Nodes, catching mistakes +@cindex Catching mistakes +@cindex Correcting mistakes +@cindex Mistakes, catching +@cindex Problems, catching +@cindex Debugging the Texinfo structure + +Besides mistakes in the content of your documentation, there are two +kinds of mistake you can make with Texinfo: you can make mistakes with +@@-commands, and you can make mistakes with the structure of the nodes +and chapters. + +Emacs has two tools for catching the @@-command mistakes and two for +catching structuring mistakes.@refill + +For finding problems with @@-commands, you can run @TeX{} or a region +formatting command on the region that has a problem; indeed, you can +run these commands on each region as you write it.@refill + +For finding problems with the structure of nodes and chapters, you can use +@kbd{C-c C-s} (@code{texinfo-show-structure}) and the related @code{occur} +command and you can use the @kbd{M-x Info-validate} command.@refill + +@menu +* makeinfo Preferred:: @code{makeinfo} finds errors. +* Debugging with Info:: How to catch errors with Info formatting. +* Debugging with TeX:: How to catch errors with @TeX{} formatting. +* Using texinfo-show-structure:: How to use @code{texinfo-show-structure}. +* Using occur:: How to list all lines containing a pattern. +* Running Info-Validate:: How to find badly referenced nodes. +@end menu + + +@node makeinfo Preferred +@section @code{makeinfo} Find Errors + +The @code{makeinfo} program does an excellent job of catching errors +and reporting them---far better than @code{texinfo-format-region} or +@code{texinfo-format-buffer}. In addition, the various functions for +automatically creating and updating node pointers and menus remove +many opportunities for human error.@refill + +If you can, use the updating commands to create and insert pointers +and menus. These prevent many errors. Then use @code{makeinfo} (or +its Texinfo mode manifestations, @code{makeinfo-region} and +@code{makeinfo-buffer}) to format your file and check for other +errors. This is the best way to work with Texinfo. But if you +cannot use @code{makeinfo}, or your problem is very puzzling, then you +may want to use the tools described in this appendix.@refill + +@node Debugging with Info +@comment node-name, next, previous, up +@section Catching Errors with Info Formatting +@cindex Catching errors with Info formatting +@cindex Debugging with Info formatting + +After you have written part of a Texinfo file, you can use the +@code{texinfo-format-region} or the @code{makeinfo-region} command to +see whether the region formats properly.@refill + +Most likely, however, you are reading this section because for some +reason you cannot use the @code{makeinfo-region} command; therefore, the +rest of this section presumes that you are using +@code{texinfo-format-region}.@refill + +If you have made a mistake with an @@-command, +@code{texinfo-format-region} will stop processing at or after the +error and display an error message. To see where in the buffer the +error occurred, switch to the @samp{*Info Region*} buffer; the cursor +will be in a position that is after the location of the error. Also, +the text will not be formatted after the place where the error +occurred (or more precisely, where it was detected).@refill + +For example, if you accidentally end a menu with the command @code{@@end +menus} with an `s' on the end, instead of with @code{@@end menu}, you +will see an error message that says:@refill + +@example +@@end menus is not handled by texinfo +@end example + +@noindent +The cursor will stop at the point in the buffer where the error +occurs, or not long after it. The buffer will look like this:@refill + +@example +@group +---------- Buffer: *Info Region* ---------- +* Menu: + +* Using texinfo-show-structure:: How to use + `texinfo-show-structure' + to catch mistakes. +* Running Info-Validate:: How to check for + unreferenced nodes. +@@end menus +@point{} +---------- Buffer: *Info Region* ---------- +@end group +@end example + +The @code{texinfo-format-region} command sometimes provides slightly +odd error messages. For example, the following cross reference fails to format:@refill + +@example +(@@xref@{Catching Mistakes, for more info.) +@end example + +@noindent +In this case, @code{texinfo-format-region} detects the missing closing +brace but displays a message that says @samp{Unbalanced parentheses} +rather than @samp{Unbalanced braces}. This is because the formatting +command looks for mismatches between braces as if they were +parentheses.@refill + +Sometimes @code{texinfo-format-region} fails to detect mistakes. For +example, in the following, the closing brace is swapped with the +closing parenthesis:@refill + +@example +(@@xref@{Catching Mistakes), for more info.@} +@end example + +@noindent +Formatting produces: +@example +(*Note for more info.: Catching Mistakes) +@end example + +The only way for you to detect this error is to realize that the +reference should have looked like this:@refill + +@example +(*Note Catching Mistakes::, for more info.) +@end example + +Incidentally, if you are reading this node in Info and type @kbd{f +@key{RET}} (@code{Info-follow-reference}), you will generate an error +message that says: + +@example +No such node: "Catching Mistakes) The only way @dots{} +@end example + +@noindent +This is because Info perceives the example of the error as the first +cross reference in this node and if you type a @key{RET} immediately +after typing the Info @kbd{f} command, Info will attempt to go to the +referenced node. If you type @kbd{f catch @key{TAB} @key{RET}}, Info +will complete the node name of the correctly written example and take +you to the `Catching Mistakes' node. (If you try this, you can return +from the `Catching Mistakes' node by typing @kbd{l} +(@code{Info-last}).) + +@c !!! section on using Elisp debugger ignored. +@ignore +Sometimes @code{texinfo-format-region} will stop long after the +original error; this is because it does not discover the problem until +then. In this case, you will need to backtrack.@refill + +@c menu +@c * Using the Emacs Lisp Debugger:: How to use the Emacs Lisp debugger. +@c end menu + +@c node Using the Emacs Lisp Debugger +@c appendixsubsec Using the Emacs Lisp Debugger +@c index Using the Emacs Lisp debugger +@c index Emacs Lisp debugger +@c index Debugger, using the Emacs Lisp + +If an error is especially elusive, you can turn on the Emacs Lisp +debugger and look at the backtrace; this tells you where in the +@code{texinfo-format-region} function the problem occurred. You can +turn on the debugger with the command:@refill + +@example +M-x set-variable @key{RET} debug-on-error @key{RET} t @key{RET} +@end example + +@noindent +and turn it off with + +@example +M-x set-variable @key{RET} debug-on-error @key{RET} nil @key{RET} +@end example + +Often, when you are using the debugger, it is easier to follow what is +going on if you use the Emacs Lisp files that are not byte-compiled. +The byte-compiled sources send octal numbers to the debugger that may +look mysterious. To use the uncompiled source files, load +@file{texinfmt.el} and @file{texinfo.el} with the @kbd{M-x load-file} +command.@refill + +The debugger will not catch an error if @code{texinfo-format-region} +does not detect one. In the example shown above, +@code{texinfo-format-region} did not find the error when the whole +list was formatted, but only when part of the list was formatted. +When @code{texinfo-format-region} did not find an error, the debugger +did not find one either. @refill + +However, when @code{texinfo-format-region} did report an error, it +invoked the debugger. This is the backtrace it produced:@refill + +@example +---------- Buffer: *Backtrace* ---------- +Signalling: (search-failed "[@},]") + re-search-forward("[@},]") + (while ...) + (let ...) + texinfo-format-parse-args() + (let ...) + texinfo-format-xref() + funcall(texinfo-format-xref) + (if ...) + (let ...) + (if ...) + (while ...) + texinfo-format-scan() + (save-excursion ...) + (let ...) + texinfo-format-region(103370 103631) +* call-interactively(texinfo-format-region) +---------- Buffer: *Backtrace* ---------- +@end example + +The backtrace is read from the bottom up. +@code{texinfo-format-region} was called interactively; and it, in +turn, called various functions, including @code{texinfo-format-scan}, +@code{texinfo-format-xref} and @code{texinfo-format-parse-args}. +Inside the function @code{texinfo-format-parse-args}, the function +@code{re-search-forward} was called; it was this function that could +not find the missing right-hand brace.@refill + +@xref{Lisp Debug, , Debugging Emacs Lisp, emacs, The GNU Emacs +Manual}, for more information.@refill +@end ignore + +@node Debugging with TeX +@comment node-name, next, previous, up +@section Catching Errors with @TeX{} Formatting +@cindex Catching errors with @TeX{} formatting +@cindex Debugging with @TeX{} formatting + +You can also catch mistakes when you format a file with @TeX{}.@refill + +Usually, you will want to do this after you have run +@code{texinfo-format-buffer} (or, better, @code{makeinfo-buffer}) on +the same file, because @code{texinfo-format-buffer} sometimes displays +error messages that make more sense than @TeX{}. (@xref{Debugging +with Info}, for more information.)@refill + +For example, @TeX{} was run on a Texinfo file, part of which is shown +here:@refill + +@example +---------- Buffer: texinfo.texi ---------- +name of the Texinfo file as an extension. The +@@samp@{??@} are `wildcards' that cause the shell to +substitute all the raw index files. (@@xref@{sorting +indices, for more information about sorting +indices.)@@refill +---------- Buffer: texinfo.texi ---------- +@end example + +@noindent +(The cross reference lacks a closing brace.) +@TeX{} produced the following output, after which it stopped:@refill + +@example +---------- Buffer: *tex-shell* ---------- +Runaway argument? +@{sorting indices, for more information about sorting +indices.) @@refill @@ETC. +! Paragraph ended before @@xref was complete. +<to be read again> + @@par +l.27 + +? +---------- Buffer: *tex-shell* ---------- +@end example + +In this case, @TeX{} produced an accurate and +understandable error message: + +@example +Paragraph ended before @@xref was complete. +@end example + +@noindent +@samp{@@par} is an internal @TeX{} command of no relevance to Texinfo. +@samp{l.27} means that @TeX{} detected the problem on line 27 of the +Texinfo file. The @samp{?} is the prompt @TeX{} uses in this +circumstance.@refill + +Unfortunately, @TeX{} is not always so helpful, and sometimes you must +truly be a Sherlock Holmes to discover what went wrong.@refill + +In any case, if you run into a problem like this, you can do one of three +things.@refill + +@enumerate +@item +You can tell @TeX{} to continue running and ignore just this error by +typing @key{RET} at the @samp{?} prompt.@refill + +@item +You can tell @TeX{} to continue running and to ignore all errors as best +it can by typing @kbd{r @key{RET}} at the @samp{?} prompt.@refill + +This is often the best thing to do. However, beware: the one error +may produce a cascade of additional error messages as its consequences +are felt through the rest of the file. To stop @TeX{} when it is +producing such an avalanche of error messages, type @kbd{C-c} (or +@kbd{C-c C-c}, if you are running a shell inside Emacs). + +@item +You can tell @TeX{} to stop this run by typing @kbd{x @key{RET}} +at the @samp{?} prompt.@refill +@end enumerate + +If you are running @TeX{} inside Emacs, you need to switch to the shell +buffer and line at which @TeX{} offers the @samp{?} prompt. + +Sometimes @TeX{} will format a file without producing error messages even +though there is a problem. This usually occurs if a command is not ended +but @TeX{} is able to continue processing anyhow. For example, if you fail +to end an itemized list with the @code{@@end itemize} command, @TeX{} will +write a DVI file that you can print out. The only error message that +@TeX{} will give you is the somewhat mysterious comment that@refill + +@example +(@@end occurred inside a group at level 1) +@end example + +@noindent +However, if you print the DVI file, you will find that the text +of the file that follows the itemized list is entirely indented as if +it were part of the last item in the itemized list. The error message +is the way @TeX{} says that it expected to find an @code{@@end} +command somewhere in the file; but that it could not determine where +it was needed.@refill + +Another source of notoriously hard-to-find errors is a missing +@code{@@end group} command. If you ever are stumped by +incomprehensible errors, look for a missing @code{@@end group} command +first.@refill + +If the Texinfo file lacks header lines, +@TeX{} may stop in the +beginning of its run and display output that looks like the following. +The @samp{*} indicates that @TeX{} is waiting for input.@refill + +@example +This is TeX, Version 3.14159 (Web2c 7.0) +(test.texinfo [1]) +* +@end example + +@noindent +In this case, simply type @kbd{\end @key{RET}} after the asterisk. Then +write the header lines in the Texinfo file and run the @TeX{} command +again. (Note the use of the backslash, @samp{\}. @TeX{} uses @samp{\} +instead of @samp{@@}; and in this circumstance, you are working +directly with @TeX{}, not with Texinfo.)@refill + +@node Using texinfo-show-structure +@comment node-name, next, previous, up +@section Using @code{texinfo-show-structure} +@cindex Showing the structure of a file +@findex texinfo-show-structure + +It is not always easy to keep track of the nodes, chapters, sections, and +subsections of a Texinfo file. This is especially true if you are revising +or adding to a Texinfo file that someone else has written.@refill + +In GNU Emacs, in Texinfo mode, the @code{texinfo-show-structure} +command lists all the lines that begin with the @@-commands that +specify the structure: @code{@@chapter}, @code{@@section}, +@code{@@appendix}, and so on. With an argument (@w{@kbd{C-u}} +as prefix argument, if interactive), +the command also shows the @code{@@node} lines. The +@code{texinfo-show-structure} command is bound to @kbd{C-c C-s} in +Texinfo mode, by default.@refill + +The lines are displayed in a buffer called the @samp{*Occur*} buffer, +indented by hierarchical level. For example, here is a part of what was +produced by running @code{texinfo-show-structure} on this manual:@refill + +@example +@group +Lines matching "^@@\\(chapter \\|sect\\|subs\\|subh\\| +unnum\\|major\\|chapheading \\|heading \\|appendix\\)" +in buffer texinfo.texi. +@dots{} +4177:@@chapter Nodes +4198: @@heading Two Paths +4231: @@section Node and Menu Illustration +4337: @@section The @@code@{@@@@node@} Command +4393: @@subheading Choosing Node and Pointer Names +4417: @@subsection How to Write an @@code@{@@@@node@} Line +4469: @@subsection @@code@{@@@@node@} Line Tips +@dots{} +@end group +@end example + +This says that lines 4337, 4393, and 4417 of @file{texinfo.texi} begin +with the @code{@@section}, @code{@@subheading}, and @code{@@subsection} +commands respectively. If you move your cursor into the @samp{*Occur*} +window, you can position the cursor over one of the lines and use the +@kbd{C-c C-c} command (@code{occur-mode-goto-occurrence}), to jump to +the corresponding spot in the Texinfo file. @xref{Other Repeating +Search, , Using Occur, emacs, The GNU Emacs Manual}, for more +information about @code{occur-mode-goto-occurrence}.@refill + +The first line in the @samp{*Occur*} window describes the @dfn{regular +expression} specified by @var{texinfo-heading-pattern}. This regular +expression is the pattern that @code{texinfo-show-structure} looks for. +@xref{Regexps, , Using Regular Expressions, emacs, The GNU Emacs Manual}, +for more information.@refill + +When you invoke the @code{texinfo-show-structure} command, Emacs will +display the structure of the whole buffer. If you want to see the +structure of just a part of the buffer, of one chapter, for example, +use the @kbd{C-x n n} (@code{narrow-to-region}) command to mark the +region. (@xref{Narrowing, , , emacs, The GNU Emacs Manual}.) This is +how the example used above was generated. (To see the whole buffer +again, use @kbd{C-x n w} (@code{widen}).)@refill + +If you call @code{texinfo-show-structure} with a prefix argument by +typing @w{@kbd{C-u C-c C-s}}, it will list lines beginning with +@code{@@node} as well as the lines beginning with the @@-sign commands +for @code{@@chapter}, @code{@@section}, and the like.@refill + +You can remind yourself of the structure of a Texinfo file by looking at +the list in the @samp{*Occur*} window; and if you have mis-named a node +or left out a section, you can correct the mistake.@refill + +@node Using occur +@comment node-name, next, previous, up +@section Using @code{occur} +@cindex Occurrences, listing with @code{@@occur} +@findex occur + +Sometimes the @code{texinfo-show-structure} command produces too much +information. Perhaps you want to remind yourself of the overall structure +of a Texinfo file, and are overwhelmed by the detailed list produced by +@code{texinfo-show-structure}. In this case, you can use the @code{occur} +command directly. To do this, type@refill + +@example +@kbd{M-x occur} +@end example + +@noindent +and then, when prompted, type a @dfn{regexp}, a regular expression for +the pattern you want to match. (@xref{Regexps, , Regular Expressions, +emacs, The GNU Emacs Manual}.) The @code{occur} command works from +the current location of the cursor in the buffer to the end of the +buffer. If you want to run @code{occur} on the whole buffer, place +the cursor at the beginning of the buffer.@refill + +For example, to see all the lines that contain the word +@samp{@@chapter} in them, just type @samp{@@chapter}. This will +produce a list of the chapters. It will also list all the sentences +with @samp{@@chapter} in the middle of the line.@refill + +If you want to see only those lines that start with the word +@samp{@@chapter}, type @samp{^@@chapter} when prompted by +@code{occur}. If you want to see all the lines that end with a word +or phrase, end the last word with a @samp{$}; for example, +@samp{catching mistakes$}. This can be helpful when you want to see +all the nodes that are part of the same chapter or section and +therefore have the same `Up' pointer.@refill + +@xref{Other Repeating Search, , Using Occur, emacs , The GNU Emacs Manual}, +for more information.@refill + +@node Running Info-Validate +@comment node-name, next, previous, up +@section Finding Badly Referenced Nodes +@findex Info-validate +@cindex Nodes, checking for badly referenced +@cindex Checking for badly referenced nodes +@cindex Looking for badly referenced nodes +@cindex Finding badly referenced nodes +@cindex Badly referenced nodes + +You can use the @code{Info-validate} command to check whether any of +the `Next', `Previous', `Up' or other node pointers fail to point to a +node. This command checks that every node pointer points to an +existing node. The @code{Info-validate} command works only on Info +files, not on Texinfo files.@refill + +The @code{makeinfo} program validates pointers automatically, so you +do not need to use the @code{Info-validate} command if you are using +@code{makeinfo}. You only may need to use @code{Info-validate} if you +are unable to run @code{makeinfo} and instead must create an Info file +using @code{texinfo-format-region} or @code{texinfo-format-buffer}, or +if you write an Info file from scratch.@refill + +@menu +* Using Info-validate:: How to run @code{Info-validate}. +* Unsplit:: How to create an unsplit file. +* Tagifying:: How to tagify a file. +* Splitting:: How to split a file manually. +@end menu + +@node Using Info-validate +@subsection Running @code{Info-validate} +@cindex Running @code{Info-validate} +@cindex Info validating a large file +@cindex Validating a large file + +To use @code{Info-validate}, visit the Info file you wish to check and +type:@refill + +@example +M-x Info-validate +@end example + +@noindent +Note that the @code{Info-validate} command requires an upper case +`I'. You may also need to create a tag table before running +@code{Info-validate}. @xref{Tagifying}. + +If your file is valid, you will receive a message that says ``File appears +valid''. However, if you have a pointer that does not point to a node, +error messages will be displayed in a buffer called @samp{*problems in +info file*}.@refill + +For example, @code{Info-validate} was run on a test file that contained +only the first node of this manual. One of the messages said:@refill + +@example +In node "Overview", invalid Next: Texinfo Mode +@end example + +@noindent +This meant that the node called @samp{Overview} had a `Next' pointer that +did not point to anything (which was true in this case, since the test file +had only one node in it).@refill + +Now suppose we add a node named @samp{Texinfo Mode} to our test case +but we do not specify a `Previous' for this node. Then we will get +the following error message:@refill + +@example +In node "Texinfo Mode", should have Previous: Overview +@end example + +@noindent +This is because every `Next' pointer should be matched by a +`Previous' (in the node where the `Next' points) which points back.@refill + +@code{Info-validate} also checks that all menu entries and cross references +point to actual nodes.@refill + +@code{Info-validate} requires a tag table and does not work with files +that have been split. (The @code{texinfo-format-buffer} command +automatically splits large files.) In order to use @code{Info-validate} +on a large file, you must run @code{texinfo-format-buffer} with an +argument so that it does not split the Info file; and you must create a +tag table for the unsplit file. + +@node Unsplit +@comment node-name, next, previous, up +@subsection Creating an Unsplit File +@cindex Creating an unsplit file +@cindex Unsplit file creation + +You can run @code{Info-validate} only on a single Info file that has a +tag table. The command will not work on the indirect subfiles that +are generated when a master file is split. If you have a large file +(longer than 300,000 bytes or so), you need to run the +@code{texinfo-format-buffer} or @code{makeinfo-buffer} command in such +a way that it does not create indirect subfiles. You will also need +to create a tag table for the Info file. After you have done this, +you can run @code{Info-validate} and look for badly referenced +nodes.@refill + +The first step is to create an unsplit Info file. To prevent +@code{texinfo-format-buffer} from splitting a Texinfo file into +smaller Info files, give a prefix to the @kbd{M-x +texinfo-format-buffer} command:@refill + +@example +C-u M-x texinfo-format-buffer +@end example + +@noindent +or else + +@example +C-u C-c C-e C-b +@end example + +@noindent +When you do this, Texinfo will not split the file and will not create +a tag table for it. @refill +@cindex Making a tag table manually +@cindex Tag table, making manually + +@node Tagifying +@subsection Tagifying a File + +After creating an unsplit Info file, you must create a tag table for +it. Visit the Info file you wish to tagify and type:@refill + +@example +M-x Info-tagify +@end example + +@noindent +(Note the upper case @samp{I} in @code{Info-tagify}.) This creates an +Info file with a tag table that you can validate.@refill + +The third step is to validate the Info file:@refill + +@example +M-x Info-validate +@end example + +@noindent +(Note the upper case @samp{I} in @code{Info-validate}.) +In brief, the steps are:@refill + +@example +@group +C-u M-x texinfo-format-buffer +M-x Info-tagify +M-x Info-validate +@end group +@end example + +After you have validated the node structure, you can rerun +@code{texinfo-format-buffer} in the normal way so it will construct a +tag table and split the file automatically, or you can make the tag +table and split the file manually.@refill + +@node Splitting +@comment node-name, next, previous, up +@subsection Splitting a File Manually +@cindex Splitting an Info file manually +@cindex Info file, splitting manually + +You should split a large file or else let the +@code{texinfo-format-buffer} or @code{makeinfo-buffer} command do it +for you automatically. (Generally you will let one of the formatting +commands do this job for you. @xref{Creating an Info File}.)@refill + +The split-off files are called the indirect subfiles.@refill + +Info files are split to save memory. With smaller files, Emacs does not +have make such a large buffer to hold the information.@refill + +If an Info file has more than 30 nodes, you should also make a tag +table for it. @xref{Using Info-validate}, for information +about creating a tag table. (Again, tag tables are usually created +automatically by the formatting command; you only need to create a tag +table yourself if you are doing the job manually. Most likely, you +will do this for a large, unsplit file on which you have run +@code{Info-validate}.)@refill + +@c Info-split is autoloaded in `loaddefs.el' in Emacs 18.51 +@ignore +Before running @code{Info-split}, you need to load the @code{info} library +into Emacs by giving the command @kbd{M-x load-library @key{RET} info +@key{RET}}. +@end ignore + +Visit the Info file you wish to tagify and split and type the two +commands:@refill + +@example +M-x Info-tagify +M-x Info-split +@end example + +@noindent +(Note that the @samp{I} in @samp{Info} is upper case.)@refill + +When you use the @code{Info-split} command, the buffer is modified into a +(small) Info file which lists the indirect subfiles. This file should be +saved in place of the original visited file. The indirect subfiles are +written in the same directory the original file is in, with names generated +by appending @samp{-} and a number to the original file name.@refill + +The primary file still functions as an Info file, but it contains just +the tag table and a directory of subfiles.@refill + + +@ignore +The simple description in the command summary seems sufficient to me +these days, so ignore this appendix. --karl, 13mar04. + +@node Refilling Paragraphs +@appendix Refilling Paragraphs +@cindex Refilling paragraphs +@cindex Filling paragraphs +@cindex Paragraphs, filling +@findex refill + +The @code{@@refill} command refills and, optionally, indents the first +line of a paragraph.@footnote{Perhaps the command should have been +called the @code{@@refillandindent} command, but @code{@@refill} is +shorter and the name was chosen before indenting was possible.} The +@code{@@refill} command is no longer important, but we describe it here +because you once needed it. You will see it in many old Texinfo +files.@refill + +Without refilling, paragraphs containing long @@-constructs may look +bad after formatting because the formatter removes @@-commands and +shortens some lines more than others. In the past, neither the +@code{texinfo-format-region} command nor the +@code{texinfo-format-buffer} command refilled paragraphs +automatically. The @code{@@refill} command had to be written at the +end of every paragraph to cause these formatters to fill them. (Both +@TeX{} and @code{makeinfo} have always refilled paragraphs +automatically.) Now, all the Info formatters automatically fill and +indent those paragraphs that need to be filled and indented.@refill + +The @code{@@refill} command causes @code{texinfo-format-region} and +@code{texinfo-format-buffer} to refill a paragraph in the Info file +@emph{after} all the other processing has been done. For this reason, +you can not use @code{@@refill} with a paragraph containing either +@code{@@*} or @code{@@w@{ @dots{} @}} since the refilling action will +override those two commands.@refill + +The @code{texinfo-format-region} and @code{texinfo-format-buffer} +commands now automatically append @code{@@refill} to the end of each +paragraph that should be filled. They do not append @code{@@refill} to +the ends of paragraphs that contain @code{@@*} or @w{@code{@@w@{ @dots{}@}}} +and therefore do not refill or indent them.@refill + +@end ignore + + +@c These are no longer ``new'', and the explanations +@c are all given elsewhere anyway, I think. --karl, 25apr97. +@c So ignore the entire appendix. +@ignore +@c node New Features, Command and Variable Index, Obtaining TeX, Top +@c appendix Second Edition Features + +@tex +% Widen the space for the first column so three control-character +% strings fit in the first column. Switched back to default .8in +% value at end of chapter. +\global\tableindent=1.0in +@end tex + +The second edition of the Texinfo manual describes more than 20 new +Texinfo mode commands and more than 50 previously undocumented Texinfo +@@-commands. This edition is more than twice the length of the first +edition.@refill + +Here is a brief description of the new commands.@refill + +@c menu +* New Texinfo Mode Commands:: The updating commands are especially useful. +* New Commands:: Many newly described @@-commands. +@c end menu + +@c node New Texinfo Mode Commands, New Commands, Obtaining TeX, Obtaining TeX +@c appendixsec New Texinfo Mode Commands + +Texinfo mode provides commands and features especially designed for +working with Texinfo files. More than 20 new commands have been +added, including commands for automatically creating and updating +both nodes and menus. This is a tedious task when done by hand.@refill + +The keybindings are intended to be somewhat mnemonic.@refill + +@c subheading Update all nodes and menus + +The @code{texinfo-master-menu} command is the primary command: + +@table @kbd +@item C-c C-u m +@itemx M-x texinfo-master-menu +Create or update a master menu. +With @kbd{C-u} as a prefix argument, +first create or update all nodes +and regular menus. +@end table + +@c subheading Update Pointers + +@noindent +Create or update `Next', `Previous', and `Up' node pointers.@refill + +@noindent +@xref{Updating Nodes and Menus}. + +@table @kbd +@item C-c C-u C-n +@itemx M-x texinfo-update-node +Update a node. + +@item C-c C-u C-e +@itemx M-x texinfo-every-node-update +Update every node in the buffer. +@end table + +@c subheading Update Menus + +@noindent +Create or update menus.@refill + +@noindent +@xref{Updating Nodes and Menus}. + +@table @kbd +@item C-c C-u C-m +@itemx M-x texinfo-make-menu +Make or update a menu. + +@item C-c C-u C-a +@itemx M-x texinfo-all-menus-update +Make or update all the menus in a buffer. +With @kbd{C-u} as a prefix argument, +first update all the nodes. +@end table + +@c subheading Insert Title as Description + +@noindent +Insert a node's chapter or section title in the space for the +description in a menu entry line; position point so you can edit the +insert. (This command works somewhat differently than the other +insertion commands, which insert only a predefined string.)@refill + +@noindent +@xref{Inserting, Inserting Frequently Used Commands}. + +@table @kbd +@item C-c C-c C-d +Insert title. +@end table + +@c subheading Format for Info + +@noindent +Provide keybindings both for the Info formatting commands that are +written in Emacs Lisp and for @code{makeinfo} that is written in +C.@refill + +@noindent +@xref{Info Formatting}. + +@noindent +Use the Emacs lisp @code{texinfo-format@dots{}} commands: + +@table @kbd +@item C-c C-e C-r +Format the region. + +@item C-c C-e C-b +Format the buffer. +@end table + +@noindent +Use @code{makeinfo}: + +@table @kbd +@item C-c C-m C-r +Format the region. + +@item C-c C-m C-b +Format the buffer. + +@item C-c C-m C-l +Recenter the @code{makeinfo} output buffer. + +@item C-c C-m C-k +Kill the @code{makeinfo} formatting job. +@end table + +@c subheading Typeset and Print + +@noindent +Typeset and print Texinfo documents from within Emacs. + +@noindent +@xref{Printing}. + +@table @kbd +@item C-c C-t C-b +Run @code{texi2dvi} on the buffer. + +@item C-c C-t C-r +Run @TeX{} on the region. + +@item C-c C-t C-i +Run @code{texindex}. + +@item C-c C-t C-p +Print the DVI file. + +@item C-c C-t C-q +Show the print queue. + +@item C-c C-t C-d +Delete a job from the print queue. + +@item C-c C-t C-k +Kill the current @TeX{} formatting job. + +@item C-c C-t C-x +Quit a currently stopped @TeX{} formatting job. + +@item C-c C-t C-l +Recenter the output buffer. +@end table + +@c subheading Other Updating Commands + +@noindent +The ``other updating commands'' do not have standard keybindings because +they are used less frequently.@refill + +@noindent +@xref{Other Updating Commands}. + +@table @kbd +@item M-x texinfo-insert-node-lines +Insert missing @code{@@node} lines using +section titles as node names. + +@item M-x texinfo-multiple-files-update +Update a multi-file document. +With a numeric prefix, such as @kbd{C-u 8}, +update @strong{every} pointer and +menu in @strong{all} the files and +then insert a master menu. + +@item M-x texinfo-indent-menu-description +Indent descriptions in menus. + +@item M-x texinfo-sequential-node-update +Insert node pointers in strict sequence. +@end table + +@c no.de New Commands, , New Texinfo Mode Commands, Obtaining TeX +@c appendix.sec New Texinfo @@-Commands + +The second edition of the Texinfo manual describes more than 50 +commands that were not described in the first edition. A third or so +of these commands existed in Texinfo but were not documented in the +manual; the others are new. Here is a listing, with brief +descriptions of them:@refill + +@c subheading Indexing + +@noindent +Create your own index, and merge indices.@refill + +@noindent +@xref{Indices}. + +@table @kbd +@item @@defindex @var{index-name} +Define a new index and its indexing command. +See also the @code{@@defcodeindex} command. + +@c written verbosely to avoid overfull hbox +@item @@synindex @var{from-index} @var{into-index} +Merge the @var{from-index} index into the @var{into-index} index. +See also the @code{@@syncodeindex} command. +@end table + +@c subheading Definitions + +@noindent +Describe functions, variables, macros, +commands, user options, special forms, and other such artifacts in a +uniform format.@refill + +@noindent +@xref{Definition Commands}. + +@table @kbd +@item @@deffn @var{category} @var{name} @var{arguments}@dots{} +Format a description for functions, interactive +commands, and similar entities. + +@item @@defvr, @@defop, @dots{} +15 other related commands. +@end table + +@c subheading Glyphs + +@noindent +Indicate the results of evaluation, expansion, +printed output, an error message, equivalence of expressions, and the +location of point.@refill + +@noindent +@xref{Glyphs}. + +@table @kbd +@item @@equiv@{@} +@itemx @equiv{} +Equivalence: + +@item @@error@{@} +@itemx @error{} +Error message + +@item @@expansion@{@} +@itemx @expansion{} +Macro expansion + +@item @@point@{@} +@itemx @point{} +Position of point + +@item @@print@{@} +@itemx @print{} +Printed output + +@item @@result@{@} +@itemx @result{} +Result of an expression +@end table + +@c subheading Page Headings + +@noindent +Customize page headings. + +@noindent +@xref{Headings}. + +@table @kbd +@item @@headings @var{on-off-single-double} +Headings on or off, single, or double-sided. + +@item @@evenfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] +Footings for even-numbered (left-hand) pages. + +@item @@evenheading, @@everyheading, @@oddheading, @dots{} +Five other related commands. + +@item @@thischapter +Insert name of chapter and chapter number. + +@item @@thischaptername, @@thisfile, @@thistitle, @@thispage +Related commands. +@end table + +@c subheading Formatting + +@noindent +Format blocks of text. + +@noindent +@xref{Quotations and Examples}, and@* +@ref{Lists and Tables, , Making Lists and Tables}. + +@table @kbd +@item @@cartouche +Draw rounded box surrounding text (no effect in Info). + +@item @@enumerate @var{optional-arg} +Enumerate a list with letters or numbers. + +@item @@exdent @var{line-of-text} +Remove indentation. + +@item @@flushleft +Left justify. + +@item @@flushright +Right justify. + +@item @@format +Do not narrow nor change font. + +@item @@ftable @var{formatting-command} +@itemx @@vtable @var{formatting-command} +Two-column table with indexing. + +@item @@lisp +For an example of Lisp code. + +@item @@smallexample +@itemx @@smalllisp +Like @@table and @@lisp, but for (originally) @@smallbook. +@end table + +@c subheading Conditionals + +@noindent +Conditionally format text. + +@noindent +@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill + +@table @kbd +@item @@set @var{flag} [@var{string}] +Set a flag. Optionally, set value +of @var{flag} to @var{string}. + +@item @@clear @var{flag} +Clear a flag. + +@item @@value@{@var{flag}@} +Replace with value to which @var{flag} is set. + +@item @@ifset @var{flag} +Format, if @var{flag} is set. + +@item @@ifclear @var{flag} +Ignore, if @var{flag} is set. +@end table + +@c subheading @@heading series for Titles + +@noindent +Produce unnumbered headings that do not appear in a table of contents. + +@noindent +@xref{Structuring}. + +@table @kbd +@item @@heading @var{title} +Unnumbered section-like heading not listed +in the table of contents of a printed manual. + +@item @@chapheading, @@majorheading, @@c subheading, @@subsubheading +Related commands. +@end table + +@need 1000 +@c subheading Font commands + +@need 1000 +@noindent +@xref{Smallcaps}, and @* +@ref{Fonts}. + +@table @kbd +@item @@r@{@var{text}@} +Print in roman font. + +@item @@sc@{@var{text}@} +Print in @sc{small caps} font. +@end table + +@c subheading Miscellaneous + +@noindent +See @ref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author} Commands},@* +see @ref{Customized Highlighting},@* +see @ref{Overfull hboxes},@* +see @ref{Footnotes},@* +see @ref{dmn, , Format a Dimension},@* +see @ref{Raise/lower sections, , @code{@@raisesections} and @code{@@lowersections}},@* +see @ref{math, , @code{@@math}: Inserting Mathematical Expressions}.@* +see @ref{minus, , Inserting a Minus Sign},@* +see @ref{paragraphindent, , Paragraph Indenting},@* +see @ref{Cross Reference Commands},@* +see @ref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author}}, and@* +see @ref{Custom Headings, , How to Make Your Own Headings}. + +@table @kbd +@item @@author @var{author} +Typeset author's name. + +@c @item @@definfoenclose @var{new-command}, @var{before}, @var{after}, +@c Define a highlighting command for Info. (Info only.) + +@item @@finalout +Produce cleaner printed output. + +@item @@footnotestyle @var{end-or-separate} +Specify footnote style, either @samp{end} or @samp{separate}. +@xref{Footnote Styles}. + +@item @@dmn@{@var{dimension}@} +Format a dimension. + +@item @@global@@let@var{new-cmd}=@var{existing-cmd} +Define a highlighting command for @TeX{}. (@TeX{} only.) + +@item @@lowersections +Reduce hierarchical level of sectioning commands. + +@item @@math@{@var{mathematical-expression}@} +Format a mathematical expression. + +@item @@minus@{@} +Generate a minus sign. + +@item @@paragraphindent @var{asis-or-number} +Specify paragraph indentation. + +@item @@raisesections +Raise hierarchical level of sectioning commands. + +@item @@ref@{@var{node-name}, @r{[}@var{entry}@r{]}, @r{[}@var{topic-or-title}@r{]}, @r{[}@var{info-file}@r{]}, @r{[}@var{manual}@r{]}@} +Make a reference. In the printed manual, the +reference does not start with the word `see'. + +@item @@title @var{title} +Typeset @var{title} in the alternative +title page format. + +@item @@subtitle @var{subtitle} +Typeset @var{subtitle} in the alternative +title page format. + +@item @@today@{@} +Insert the current date. +@end table +@tex +% Switch width of first column of tables back to default value +\global\tableindent=.8in +@end tex +@end ignore + + +@node GNU Free Documentation License +@appendix GNU Free Documentation License + +@include fdl.texi + + +@node Command and Variable Index +@unnumbered Command and Variable Index + +This is an alphabetical list of all the @@-commands, assorted Emacs Lisp +functions, and several variables. To make the list easier to use, the +commands are listed without their preceding @samp{@@}.@refill + +@printindex fn + + +@node General Index +@unnumbered General Index + +@printindex cp + + +@bye |