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Diffstat (limited to 'doc/gawk.texi')
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1 files changed, 612 insertions, 3 deletions
diff --git a/doc/gawk.texi b/doc/gawk.texi index b759986b..1001d03c 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -402,7 +402,8 @@ particular records in a file and perform operations upon them. field. * Command Line Field Separator:: Setting @code{FS} from the command-line. -* Full Line Fields:: Making the full line be a single field. +* Full Line Fields:: Making the full line be a single + field. * Field Splitting Summary:: Some final points and a summary table. * Constant Size:: Reading constant width data. * Splitting By Content:: Defining Fields By Content @@ -792,6 +793,7 @@ particular records in a file and perform operations upon them. version of @command{awk}. * POSIX/GNU:: The extensions in @command{gawk} not in POSIX @command{awk}. +* Feature History:: The history of the features in @command{gawk}. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. @@ -33025,6 +33027,7 @@ of the @value{DOCUMENT} where you can find more information. @command{awk}. * POSIX/GNU:: The extensions in @command{gawk} not in POSIX @command{awk}. +* Feature History:: The history of the features in @command{gawk}. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. * Contributors:: The major contributors to @command{gawk}. @@ -33603,6 +33606,612 @@ GCC for VAX and Alpha has not been tested for a while. @c ENDOFRANGE exgnot @c ENDOFRANGE posnot +@node Feature History +@appendixsec History of @command{gawk} Features + +@ignore +See the thread: +https://groups.google.com/forum/#!topic/comp.lang.awk/SAUiRuff30c +This motivated me to add this section. +@end ignore + +@ignore +I've tried to follow this general order, esp.@: for the 3.0 and 3.1 sections: + variables + special files + language changes (e.g., hex constants) + differences in standard awk functions + new gawk functions + new keywords + new command-line options + behavioral changes + new ports +Within each category, be alphabetical. +@end ignore + +This @value{SECTION} describes the features in @command{gawk} +over and above those in POSIX @command{awk}, +in the order they were added to @command{gawk}. + +Version 2.10 of @command{gawk} introduced the following features: + +@itemize @bullet +@item +The @env{AWKPATH} environment variable for specifying a path search for +the @option{-f} command-line option +(@pxref{Options}). + +@item +The @code{IGNORECASE} variable and its effects +(@pxref{Case-sensitivity}). + +@item +The @file{/dev/stdin}, @file{/dev/stdout}, @file{/dev/stderr} and +@file{/dev/fd/@var{N}} special file names +(@pxref{Special Files}). +@end itemize + +Version 2.13 of @command{gawk} introduced the following features: + +@itemize @bullet +@item +The @code{FIELDWIDTHS} variable and its effects +(@pxref{Constant Size}). + +@item +The @code{systime()} and @code{strftime()} built-in functions for obtaining +and printing timestamps +(@pxref{Time Functions}). + +@item +Additional command-line options +(@pxref{Options}): + +@itemize @minus +@item +The @option{-W lint} option to provide error and portability checking +for both the source code and at runtime. + +@item +The @option{-W compat} option to turn off the GNU extensions. + +@item +The @option{-W posix} option for full POSIX compliance. +@end itemize +@end itemize + +Version 2.14 of @command{gawk} introduced the following feature: + +@itemize @bullet +@item +The @code{next file} statement for skipping to the next data file +(@pxref{Nextfile Statement}). +@end itemize + +Version 2.15 of @command{gawk} introduced the following features: + +@itemize @bullet +@item +New variables (@pxref{Built-in Variables}): + +@itemize @minus +@item +@code{ARGIND}, which tracks the movement of @code{FILENAME} +through @code{ARGV}. + +@item +@code{ERRNO}, which contains the system error message when +@code{getline} returns @minus{}1 or @code{close()} fails. +@end itemize + +@item +The @file{/dev/pid}, @file{/dev/ppid}, @file{/dev/pgrpid}, and +@file{/dev/user} special file names. These have since been removed. + +@item +The ability to delete all of an array at once with @samp{delete @var{array}} +(@pxref{Delete}). + +@item +Command line option changes +(@pxref{Options}): + +@itemize @minus +@item +The ability to use GNU-style long-named options that start with @option{--}. + +@item +The @option{--source} option for mixing command-line and library-file +source code. +@end itemize +@end itemize + +Version 3.0 of @command{gawk} introduced the following features: + +@itemize @bullet +@item +New or changed variables: + +@itemize @minus +@item +@code{IGNORECASE} changed, now applying to string comparison as well +as regexp operations +(@pxref{Case-sensitivity}). + +@item +@code{RT}, which contains the input text that matched @code{RS} +(@pxref{Records}). +@end itemize + +@item +Full support for both POSIX and GNU regexps +(@pxref{Regexp}). + +@item +The @code{gensub()} function for more powerful text manipulation +(@pxref{String Functions}). + +@item +The @code{strftime()} function acquired a default time format, +allowing it to be called with no arguments +(@pxref{Time Functions}). + +@item +The ability for @code{FS} and for the third +argument to @code{split()} to be null strings +(@pxref{Single Character Fields}). + +@item +The ability for @code{RS} to be a regexp +(@pxref{Records}). + +@item +The @code{next file} statement became @code{nextfile} +(@pxref{Nextfile Statement}). + +@item +The @code{fflush()} function from the +Bell Laboratories research version of @command{awk} +(@pxref{I/O Functions}). + +@item +New command line options: + +@itemize @minus +@item +The @option{--lint-old} option to +warn about constructs that are not available in +the original Version 7 Unix version of @command{awk} +(@pxref{V7/SVR3.1}). + +@item +The @option{-m} option from the +Bell Laboratories research version of @command{awk} +This was later removed. + +@item +The @option{--re-interval} option to provide interval expressions in regexps +(@pxref{Regexp Operators}). + +@item +The @option{--traditional} option was added as a better name for +@option{--compat} (@pxref{Options}). +@end itemize + +@item +The use of GNU Autoconf to control the configuration process +(@pxref{Quick Installation}). + +@item +Amiga support. + +@end itemize + +Version 3.1 of @command{gawk} introduced the following features: + +@itemize @bullet +@item +New variables +(@pxref{Built-in Variables}): + +@itemize @minus +@item +@code{BINMODE}, for non-POSIX systems, +which allows binary I/O for input and/or output files +(@pxref{PC Using}). + +@item +@code{LINT}, which dynamically controls lint warnings. + +@item +@code{PROCINFO}, an array for providing process-related information. + +@item +@code{TEXTDOMAIN}, for setting an application's internationalization text domain +(@pxref{Internationalization}). +@end itemize + +@item +The ability to use octal and hexadecimal constants in @command{awk} +program source code +(@pxref{Nondecimal-numbers}). + +@item +The @samp{|&} operator for two-way I/O to a coprocess +(@pxref{Two-way I/O}). + +@item +The @file{/inet} special files for TCP/IP networking using @samp{|&} +(@pxref{TCP/IP Networking}). + +@item +The optional second argument to @code{close()} that allows closing one end +of a two-way pipe to a coprocess +(@pxref{Two-way I/O}). + +@item +The optional third argument to the @code{match()} function +for capturing text-matching subexpressions within a regexp +(@pxref{String Functions}). + +@item +Positional specifiers in @code{printf} formats for +making translations easier +(@pxref{Printf Ordering}). + +@item +A number of new built-in functions: + +@itemize @minus +@item +The @code{asort()} and @code{asorti()} functions for sorting arrays +(@pxref{Array Sorting}). + +@item +The @code{bindtextdomain()}, @code{dcgettext()} and @code{dcngettext()} functions +for internationalization +(@pxref{Programmer i18n}). + +@item +The @code{extension()} function and the ability to add +new built-in functions dynamically +(@pxref{Dynamic Extensions}). + +@item +The @code{mktime()} function for creating timestamps +(@pxref{Time Functions}). + +@item +The @code{and()}, @code{or()}, @code{xor()}, @code{compl()}, +@code{lshift()}, @code{rshift()}, and @code{strtonum()} functions +(@pxref{Bitwise Functions}). +@end itemize + +@item +@cindex @code{next file} statement +The support for @samp{next file} as two words was removed completely +(@pxref{Nextfile Statement}). + +@item +Additional commnd line options +(@pxref{Options}): + +@itemize @minus +@item +The @option{--dump-variables} option to print a list of all global variables. + +@item +The @option{--exec} option, for use in CGI scripts. + +@item +The @option{--gen-po} command-line option and the use of a leading +underscore to mark strings that should be translated +(@pxref{String Extraction}). + +@item +The @option{--non-decimal-data} option to allow non-decimal +input data +(@pxref{Nondecimal Data}). + +@item +The @option{--profile} option and @command{pgawk}, the +profiling version of @command{gawk}, for producing execution +profiles of @command{awk} programs +(@pxref{Profiling}). + +@item +The @option{--use-lc-numeric} option to force @command{gawk} +to use the locale's decimal point for parsing input data +(@pxref{Conversion}). +@end itemize + +@item +The use of GNU Automake to help in standardizing the configuration process +(@pxref{Quick Installation}). + +@item +The use of GNU @code{gettext} for @command{gawk}'s own message output +(@pxref{Gawk I18N}). + +@item +BeOS support. This was later removed. + +@item +Tandem support. This was later removed. + +@item +The Atari port became officially unsupported. + +@item +The source code changed to use ISO C standard-style function definitions. + +@item +POSIX compliance for @code{sub()} and @code{gsub()} +(@pxref{Gory Details}). + +@item +The @code{length()} function was extended to accept an array argument +and return the number of elements in the array +(@pxref{String Functions}). + +@item +The @code{strftime()} function acquired a third argument to +enable printing times as UTC +(@pxref{Time Functions}). +@end itemize + +Version 4.0 of @command{gawk} introduced the following features: + +@itemize @bullet + +@item +Variable additions: + +@itemize @minus +@item +@code{FPAT}, which allows you to specify a regexp that matches +the fields, instead of matching the field separator +(@pxref{Splitting By Content}). + +@item +If @code{PROCINFO["sorted_in"]} exists, @samp{for(iggy in foo)} loops sort the +indices before looping over them. The value of this element +provides control over how the indices are sorted before the loop +traversal starts +(@pxref{Controlling Scanning}). + +@item +@code{PROCINFO["strftime"]}, which holds +the default format for @code{strftime()} +(@pxref{Time Functions}). +@end itemize + +@item +The special files @file{/dev/pid}, @file{/dev/ppid}, @file{/dev/pgrpid} +and @file{/dev/user} were removed. + +@item +Support for IPv6 was added via the @file{/inet6} special file. +@file{/inet4} forces IPv4 and @file{/inet} chooses the system +default, which is probably IPv4 +(@pxref{TCP/IP Networking}). + +@item +The use of @samp{\s} and @samp{\S} escape sequences in regular expressions +(@pxref{GNU Regexp Operators}). + +@item +Interval expressions became part of default regular expressions +(@pxref{Regexp Operators}). + +@item +POSIX character classes work even with @option{--traditional} +(@pxref{Regexp Operators}). + +@item +@code{break} and @code{continue} became invalid outside a loop, +even with @option{--traditional} +(@pxref{Break Statement}, and also see +@ref{Continue Statement}). + +@item +@code{fflush()}, @code{nextfile}, and @samp{delete @var{array}} +are allowed if @option{--posix} or @option{--traditional}, since they +are all now part of POSIX. + +@item +An optional third argument to +@code{asort()} and @code{asorti()}, specifying how to sort +(@pxref{String Functions}). + +@item +The behavior of @code{fflush()} changed to match Brian Kernighan's @command{awk} +and for POSIX; now both @samp{fflush()} and @samp{fflush("")} +flush all open output redirections +(@pxref{I/O Functions}). + +@item +The @code{isarray()} +function which distinguishes if an item is an array +or not, to make it possible to traverse multidimensional arrays +(@pxref{Type Functions}). + +@item +The @code{patsplit()} +function which gives the same capability as @code{FPAT}, for splitting +(@pxref{String Functions}). + +@item +An optional fourth argument to the @code{split()} function, +which is an array to hold the values of the separators +(@pxref{String Functions}). + +@item +Arrays of arrays +(@pxref{Arrays of Arrays}). + +@item +The @code{BEGINFILE} and @code{ENDFILE} special patterns +(@pxref{BEGINFILE/ENDFILE}). + +@item +Indirect function calls +(@pxref{Indirect Calls}). + +@item +@code{switch} / @code{case} are enabled by default +(@pxref{Switch Statement}). + +@item +Command line option changes +(@pxref{Options}): + +@itemize @minus +@item +The @option{-b} and @option{--characters-as-bytes} options +which prevent @command{gawk} from treating input as a multibyte string. + +@item +The redundant @option{--compat}, @option{--copyleft}, and @option{--usage} +long options were removed. + +@item +The @option{--gen-po} option was finally renamed to the correct @option{--gen-pot}. + +@item +The @option{--sandbox} option which disables certain features. + +@item +All long options acquired corresponding short options, for use in @samp{#!} scripts. +@end itemize + +@item +Directories named on the command line now produce a warning, not a fatal +error, unless @option{--posix} or @option{--traditional} are used +(@pxref{Command line directories}). + +@item +The @command{gawk} internals were rewritten, bringing the @command{dgawk} +debugger and possibly improved performance +(@pxref{Debugger}). + +@item +Per the GNU Coding Standards, dynamic extensions must now define +a global symbol indicating that they are GPL-compatible +(@pxref{Plugin License}). + +@item +In POSIX mode, string comparisons use @code{strcoll()} / @code{wcscoll()} +(@pxref{POSIX String Comparison}). + +@item +The option for raw sockets was removed, since it was never implemented +(@pxref{TCP/IP Networking}). + +@item +Ranges of the form @code{[d-h]} are treated as if they were in the +C locale, no matter what kind of regexp is being used, and even if +@option{--posix} +(@pxref{Ranges and Locales}). + +@item +Support was removed for the following systems: + +@itemize @minus +@item +Atari + +@item +Amiga + +@item +BeOS + +@item +Cray + +@item +MIPS RiscOS + +@item +MS-DOS with Microsoft Compiler + +@item +MS-Windows with Microsoft Compiler + +@item +NeXT + +@item +SunOS 3.x, Sun 386 (Road Runner) + +@item +Tandem (non-POSIX) + +@item +Prestandard VAX C compiler for VAX/VMS +@end itemize +@end itemize + +Version 4.1 of @command{gawk} introduced the following features: + +@itemize @bullet + +@item +Three new arrays: +@code{SYMTAB}, @code{FUNCTAB}, and @code{PROCINFO["identifiers"]} +(@pxref{Auto-set}). + +@item +The three executables @command{gawk}, @command{pgawk}, and @command{dgawk}, were merged into +one, named just @command{gawk}. As a result the command line options changed. + +@item +Command line option changes +(@pxref{Options}): + +@itemize @minus +@item +The @option{-D} option invokes the debugger. + +@item +The @option{-i} and @option{--include} options +load @command{awk} library files. + +@item +The @option{-l} and @option{--load} options for load compiled dynamic extensions. + +@item +The @option{-M} and @option{--bignum} options enable MPFR. + +@item +The @option{-o} only does pretty-printing. + +@item +The @option{-p} option is used for profiling. + +@item +The @option{-R} option was removed. +@end itemize + +@item +Support for high precision arithmetic with MPFR. +(@pxref{Gawk and MPFR}). + +@item +The @code{and()}, @code{or()} and @code{xor()} functions +allow any number of arguments, +with a minimum of two +(@pxref{Bitwise Functions}). + +@item +The dynamic extension interface was completely redone +(@pxref{Dynamic Extensions}). + +@end itemize + +@c XXX ADD MORE STUFF HERE + @node Common Extensions @appendixsec Common Extensions Summary @@ -33618,7 +34227,7 @@ the three most widely-used freely available versions of @command{awk} @item @samp{\x} Escape sequence @tab X @tab X @tab X @item @code{RS} as regexp @tab @tab X @tab X @item @code{FS} as null string @tab X @tab X @tab X -@item @file{/dev/stdin} special file @tab X @tab @tab X +@item @file{/dev/stdin} special file @tab X @tab X @tab X @item @file{/dev/stdout} special file @tab X @tab X @tab X @item @file{/dev/stderr} special file @tab X @tab X @tab X @item @code{**} and @code{**=} operators @tab X @tab @tab X @@ -33626,7 +34235,7 @@ the three most widely-used freely available versions of @command{awk} @item @code{func} keyword @tab X @tab @tab X @item @code{nextfile} statement @tab X @tab X @tab X @item @code{delete} without subscript @tab X @tab X @tab X -@item @code{length()} of an array @tab X @tab @tab X +@item @code{length()} of an array @tab X @tab X @tab X @item @code{BINMODE} variable @tab @tab X @tab X @item Time related functions @tab @tab X @tab X @end multitable |