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diff --git a/doc/bashref.info b/doc/bashref.info index fe2b2481..8286ffd8 100644 --- a/doc/bashref.info +++ b/doc/bashref.info @@ -2,9 +2,9 @@ This is bashref.info, produced by makeinfo version 6.8 from bashref.texi. This text is a brief description of the features that are present in the -Bash shell (version 5.2, 20 April 2023). +Bash shell (version 5.2, 14 May 2023). - This is Edition 5.2, last updated 20 April 2023, of 'The GNU Bash + This is Edition 5.2, last updated 14 May 2023, of 'The GNU Bash Reference Manual', for 'Bash', Version 5.2. Copyright (C) 1988-2023 Free Software Foundation, Inc. @@ -27,10 +27,10 @@ Bash Features ************* This text is a brief description of the features that are present in the -Bash shell (version 5.2, 20 April 2023). The Bash home page is +Bash shell (version 5.2, 14 May 2023). The Bash home page is <http://www.gnu.org/software/bash/>. - This is Edition 5.2, last updated 20 April 2023, of 'The GNU Bash + This is Edition 5.2, last updated 14 May 2023, of 'The GNU Bash Reference Manual', for 'Bash', Version 5.2. Bash contains features that appear in other popular shells, and some @@ -419,8 +419,8 @@ File: bashref.info, Node: ANSI-C Quoting, Next: Locale Translation, Prev: Dou 3.1.2.4 ANSI-C Quoting ...................... -Character sequences of the form $'STRING' are treated as a special kind -of single quotes. The sequence expands to STRING, with +Character sequences of the form '$'STRING'' are treated as a special +kind of single quotes. The sequence expands to STRING, with backslash-escaped characters in STRING replaced as specified by the ANSI C standard. Backslash escape sequences, if present, are decoded as follows: @@ -2240,11 +2240,11 @@ File: bashref.info, Node: Command Substitution, Next: Arithmetic Expansion, P -------------------------- Command substitution allows the output of a command to replace the -command itself. Command substitution occurs when a command is enclosed -as follows: +command itself. The standard form of command substitution occurs when a +command is enclosed as follows: $(COMMAND) -or - `COMMAND` +or (deprecated) + `COMMAND`. Bash performs the expansion by executing COMMAND in a subshell environment and replacing the command substitution with the standard @@ -2253,17 +2253,64 @@ newlines are not deleted, but they may be removed during word splitting. The command substitution '$(cat FILE)' can be replaced by the equivalent but faster '$(< FILE)'. - When the old-style backquote form of substitution is used, backslash -retains its literal meaning except when followed by '$', '`', or '\'. -The first backquote not preceded by a backslash terminates the command + With the old-style backquote form of substitution, backslash retains +its literal meaning except when followed by '$', '`', or '\'. The first +backquote not preceded by a backslash terminates the command substitution. When using the '$(COMMAND)' form, all characters between the parentheses make up the command; none are treated specially. + There is an alternate form of command substitution: + + ${C COMMAND; } + +which executes COMMAND in the current execution environment. This means +that side effects of COMMAND take effect immediately in the current +execution environment and persist in the current environment after the +command completes (e.g., the 'exit' builtin will exit the shell). + + The character C following the open brace must be a space, tab, +newline, '(', or '|', and the close brace must be in a position where a +reserved word may appear (i.e., preceded by a command terminator such as +semicolon). Bash allows the close brace to be joined to the remaining +characters in the word without being followed by a shell metacharacter +as a reserved word would usually require. + + This type of command substitution superficially resembles executing +an unnamed shell function: local variables are created as when a shell +function is executing, and the 'return' builtin forces COMMAND to +complete; however, the rest of the execution environment, including the +positional parameters, is shared with the caller. + + If the first character following the open brace is a '(', COMMAND is +executed in a subshell, and COMMAND must be terminated by a ')'. This +is similar to the '(' compound command (*note Command Grouping::). If +the first character is a '|', the construct expands to the value of the +'REPLY' shell variable after COMMAND executes, without removing any +trailing newlines, and the standard output of COMMAND remains the same +as in the calling shell. Bash creates 'REPLY' as an initially-unset +local variable when COMMAND executes, and restores 'REPLY' to the value +it had before the command substitution after COMMAND completes, as with +any local variable. + + For example, this construct expands to '12345', and leaves the shell +variable 'X' unchanged in the current execution environment: + + ${ local X=12345 ; echo $X; } + +(not declaring 'X' as local would modify its value in the current +environment, as with normal shell function execution), while this +construct does not require any output to expand to '12345': + + ${| REPLY=12345; } + +and restores 'REPLY' to the value it had before the command +substitution. + Command substitutions may be nested. To nest when using the backquoted form, escape the inner backquotes with backslashes. - If the substitution appears within double quotes, word splitting and -filename expansion are not performed on the results. + If the substitution appears within double quotes, Bash does not +perform word splitting and filename expansion on the results. File: bashref.info, Node: Arithmetic Expansion, Next: Process Substitution, Prev: Command Substitution, Up: Shell Expansions @@ -12707,138 +12754,138 @@ D.5 Concept Index Tag Table: -Node: Top891 -Node: Introduction2805 -Node: What is Bash?3021 -Node: What is a shell?4135 -Node: Definitions6673 -Node: Basic Shell Features9624 -Node: Shell Syntax10843 -Node: Shell Operation11869 -Node: Quoting13162 -Node: Escape Character14466 -Node: Single Quotes14951 -Node: Double Quotes15299 -Node: ANSI-C Quoting16577 -Node: Locale Translation17887 -Node: Creating Internationalized Scripts19198 -Node: Comments23315 -Node: Shell Commands23933 -Node: Reserved Words24871 -Node: Simple Commands25627 -Node: Pipelines26281 -Node: Lists29280 -Node: Compound Commands31075 -Node: Looping Constructs32087 -Node: Conditional Constructs34582 -Node: Command Grouping49070 -Node: Coprocesses50548 -Node: GNU Parallel53211 -Node: Shell Functions54128 -Node: Shell Parameters62013 -Node: Positional Parameters66401 -Node: Special Parameters67303 -Node: Shell Expansions70517 -Node: Brace Expansion72644 -Node: Tilde Expansion75378 -Node: Shell Parameter Expansion77999 -Node: Command Substitution96401 -Node: Arithmetic Expansion97756 -Node: Process Substitution98724 -Node: Word Splitting99844 -Node: Filename Expansion101892 -Node: Pattern Matching104825 -Node: Quote Removal109827 -Node: Redirections110122 -Node: Executing Commands119815 -Node: Simple Command Expansion120485 -Node: Command Search and Execution122595 -Node: Command Execution Environment124982 -Node: Environment128017 -Node: Exit Status129680 -Node: Signals131464 -Node: Shell Scripts134913 -Node: Shell Builtin Commands137940 -Node: Bourne Shell Builtins139978 -Node: Bash Builtins162177 -Node: Modifying Shell Behavior194176 -Node: The Set Builtin194521 -Node: The Shopt Builtin205119 -Node: Special Builtins221031 -Node: Shell Variables222010 -Node: Bourne Shell Variables222447 -Node: Bash Variables224551 -Node: Bash Features258616 -Node: Invoking Bash259629 -Node: Bash Startup Files265642 -Node: Interactive Shells270773 -Node: What is an Interactive Shell?271184 -Node: Is this Shell Interactive?271833 -Node: Interactive Shell Behavior272648 -Node: Bash Conditional Expressions276277 -Node: Shell Arithmetic280919 -Node: Aliases283880 -Node: Arrays286774 -Node: The Directory Stack293337 -Node: Directory Stack Builtins294121 -Node: Controlling the Prompt298381 -Node: The Restricted Shell301346 -Node: Bash POSIX Mode303956 -Node: Shell Compatibility Mode319749 -Node: Job Control327993 -Node: Job Control Basics328453 -Node: Job Control Builtins333455 -Node: Job Control Variables339250 -Node: Command Line Editing340406 -Node: Introduction and Notation342077 -Node: Readline Interaction343700 -Node: Readline Bare Essentials344891 -Node: Readline Movement Commands346680 -Node: Readline Killing Commands347640 -Node: Readline Arguments349561 -Node: Searching350605 -Node: Readline Init File352791 -Node: Readline Init File Syntax354052 -Node: Conditional Init Constructs377843 -Node: Sample Init File382039 -Node: Bindable Readline Commands385163 -Node: Commands For Moving386367 -Node: Commands For History388418 -Node: Commands For Text393412 -Node: Commands For Killing397061 -Node: Numeric Arguments400094 -Node: Commands For Completion401233 -Node: Keyboard Macros405424 -Node: Miscellaneous Commands406112 -Node: Readline vi Mode412150 -Node: Programmable Completion413057 -Node: Programmable Completion Builtins420837 -Node: A Programmable Completion Example431825 -Node: Using History Interactively437073 -Node: Bash History Facilities437757 -Node: Bash History Builtins440762 -Node: History Interaction445786 -Node: Event Designators449406 -Node: Word Designators450760 -Node: Modifiers452520 -Node: Installing Bash454328 -Node: Basic Installation455465 -Node: Compilers and Options459187 -Node: Compiling For Multiple Architectures459928 -Node: Installation Names461620 -Node: Specifying the System Type463729 -Node: Sharing Defaults464446 -Node: Operation Controls465119 -Node: Optional Features466077 -Node: Reporting Bugs477296 -Node: Major Differences From The Bourne Shell478630 -Node: GNU Free Documentation License495479 -Node: Indexes520656 -Node: Builtin Index521110 -Node: Reserved Word Index527937 -Node: Variable Index530385 -Node: Function Index547373 -Node: Concept Index561157 +Node: Top887 +Node: Introduction2797 +Node: What is Bash?3013 +Node: What is a shell?4127 +Node: Definitions6665 +Node: Basic Shell Features9616 +Node: Shell Syntax10835 +Node: Shell Operation11861 +Node: Quoting13154 +Node: Escape Character14458 +Node: Single Quotes14943 +Node: Double Quotes15291 +Node: ANSI-C Quoting16569 +Node: Locale Translation17881 +Node: Creating Internationalized Scripts19192 +Node: Comments23309 +Node: Shell Commands23927 +Node: Reserved Words24865 +Node: Simple Commands25621 +Node: Pipelines26275 +Node: Lists29274 +Node: Compound Commands31069 +Node: Looping Constructs32081 +Node: Conditional Constructs34576 +Node: Command Grouping49064 +Node: Coprocesses50542 +Node: GNU Parallel53205 +Node: Shell Functions54122 +Node: Shell Parameters62007 +Node: Positional Parameters66395 +Node: Special Parameters67297 +Node: Shell Expansions70511 +Node: Brace Expansion72638 +Node: Tilde Expansion75372 +Node: Shell Parameter Expansion77993 +Node: Command Substitution96395 +Node: Arithmetic Expansion99987 +Node: Process Substitution100955 +Node: Word Splitting102075 +Node: Filename Expansion104123 +Node: Pattern Matching107056 +Node: Quote Removal112058 +Node: Redirections112353 +Node: Executing Commands122046 +Node: Simple Command Expansion122716 +Node: Command Search and Execution124826 +Node: Command Execution Environment127213 +Node: Environment130248 +Node: Exit Status131911 +Node: Signals133695 +Node: Shell Scripts137144 +Node: Shell Builtin Commands140171 +Node: Bourne Shell Builtins142209 +Node: Bash Builtins164408 +Node: Modifying Shell Behavior196407 +Node: The Set Builtin196752 +Node: The Shopt Builtin207350 +Node: Special Builtins223262 +Node: Shell Variables224241 +Node: Bourne Shell Variables224678 +Node: Bash Variables226782 +Node: Bash Features260847 +Node: Invoking Bash261860 +Node: Bash Startup Files267873 +Node: Interactive Shells273004 +Node: What is an Interactive Shell?273415 +Node: Is this Shell Interactive?274064 +Node: Interactive Shell Behavior274879 +Node: Bash Conditional Expressions278508 +Node: Shell Arithmetic283150 +Node: Aliases286111 +Node: Arrays289005 +Node: The Directory Stack295568 +Node: Directory Stack Builtins296352 +Node: Controlling the Prompt300612 +Node: The Restricted Shell303577 +Node: Bash POSIX Mode306187 +Node: Shell Compatibility Mode321980 +Node: Job Control330224 +Node: Job Control Basics330684 +Node: Job Control Builtins335686 +Node: Job Control Variables341481 +Node: Command Line Editing342637 +Node: Introduction and Notation344308 +Node: Readline Interaction345931 +Node: Readline Bare Essentials347122 +Node: Readline Movement Commands348911 +Node: Readline Killing Commands349871 +Node: Readline Arguments351792 +Node: Searching352836 +Node: Readline Init File355022 +Node: Readline Init File Syntax356283 +Node: Conditional Init Constructs380074 +Node: Sample Init File384270 +Node: Bindable Readline Commands387394 +Node: Commands For Moving388598 +Node: Commands For History390649 +Node: Commands For Text395643 +Node: Commands For Killing399292 +Node: Numeric Arguments402325 +Node: Commands For Completion403464 +Node: Keyboard Macros407655 +Node: Miscellaneous Commands408343 +Node: Readline vi Mode414381 +Node: Programmable Completion415288 +Node: Programmable Completion Builtins423068 +Node: A Programmable Completion Example434056 +Node: Using History Interactively439304 +Node: Bash History Facilities439988 +Node: Bash History Builtins442993 +Node: History Interaction448017 +Node: Event Designators451637 +Node: Word Designators452991 +Node: Modifiers454751 +Node: Installing Bash456559 +Node: Basic Installation457696 +Node: Compilers and Options461418 +Node: Compiling For Multiple Architectures462159 +Node: Installation Names463851 +Node: Specifying the System Type465960 +Node: Sharing Defaults466677 +Node: Operation Controls467350 +Node: Optional Features468308 +Node: Reporting Bugs479527 +Node: Major Differences From The Bourne Shell480861 +Node: GNU Free Documentation License497710 +Node: Indexes522887 +Node: Builtin Index523341 +Node: Reserved Word Index530168 +Node: Variable Index532616 +Node: Function Index549604 +Node: Concept Index563388 End Tag Table |