pmodules/bash
0
0
Fork 0
mirror of https://https.git.savannah.gnu.org/git/bash.git synced 2026-07-14 07:30:49 +02:00
Code Issues Packages Projects Releases Wiki Activity

bash-5.0-beta release

Browse Source
This commit is contained in:
Chet Ramey
2018-09-17 15:10:56 -04:00
parent 9a51695bed
commit 2f5dfe5a18
144 changed files with 27560 additions and 36005 deletions
Download Patch File Download Diff File Expand all files Collapse all files
doc/bashref.texi
+64 -23
View File
@@ -876,7 +876,9 @@ zero if no condition tested true.
The syntax of the @code{case} command is:
@example
case @var{word} in [ [(] @var{pattern} [| @var{pattern}]@dots{}) @var{command-list} ;;]@dots{} esac
case @var{word} in
[ [(] @var{pattern} [| @var{pattern}]@dots{}) @var{command-list} ;;]@dots{}
esac
@end example
@code{case} will selectively execute the @var{command-list} corresponding to
@@ -1028,7 +1030,8 @@ to be matched as a string.
An additional binary operator, @samp{=~}, is available, with the same
precedence as @samp{==} and @samp{!=}.
When it is used, the string to the right of the operator is considered
an extended regular expression and matched accordingly (as in @i{regex}3)).
a @sc{POSIX} extended regular expression and matched accordingly
(as in @i{regex}3)).
The return value is 0 if the string matches
the pattern, and 1 otherwise.
If the regular expression is syntactically incorrect, the conditional
@@ -1283,7 +1286,8 @@ from a file (in this case, filenames listed one per line):
@noindent
with a more compact syntax reminiscent of lambdas:
@example
cat list | parallel "do-something1 @{@} config-@{@} ; do-something2 < @{@}" | process-output
cat list | parallel "do-something1 @{@} config-@{@} ; do-something2 < @{@}" |
process-output
@end example
Parallel provides a built-in mechanism to remove filename extensions, which
@@ -1306,13 +1310,21 @@ parallel "zcat @{@} | bzip2 >@{.@}.bz2 && rm @{@}" ::: *.gz
If a command generates output, you may want to preserve the input order in
the output. For instance, the following command
@example
@{ echo foss.org.my ; echo debian.org; echo freenetproject.org; @} | parallel traceroute
@{
echo foss.org.my ;
echo debian.org ;
echo freenetproject.org ;
@} | parallel traceroute
@end example
@noindent
will display as output the traceroute invocation that finishes first.
Adding the @option{-k} option
@example
@{ echo foss.org.my ; echo debian.org; echo freenetproject.org; @} | parallel -k traceroute
@{
echo foss.org.my ;
echo debian.org ;
echo freenetproject.org ;
@} | parallel -k traceroute
@end example
@noindent
will ensure that the output of @code{traceroute foss.org.my} is displayed first.
@@ -1663,8 +1675,16 @@ separators.
@item @@
@vindex $@@
($@@) Expands to the positional parameters, starting from one. When the
expansion occurs within double quotes, each parameter expands to a
($@@) Expands to the positional parameters, starting from one.
In contexts where word splitting is performed, this expands each
positional parameter to a separate word; if not within double
quotes, these words are subject to word splitting.
In contexts where word splitting is not performed,
this expands to a single word
with each positional parameter separated by a space.
When the
expansion occurs within double quotes, and word splitting is performed,
each parameter expands to a
separate word. That is, @code{"$@@"} is equivalent to
@code{"$1" "$2" @dots{}}.
If the double-quoted expansion occurs within a word, the expansion of
@@ -1926,6 +1946,12 @@ The string that would be displayed by @samp{dirs +@var{N}}
The string that would be displayed by @samp{dirs -@var{N}}
@end table
Bash also performs tilde expansion on words satisfying the conditions of
variable assignments (@pxref{Shell Parameters})
when they appear as arguments to simple commands.
Bash does not do this, except for the @var{declaration} commands listed
above, when in @sc{posix} mode.
@node Shell Parameter Expansion
@subsection Shell Parameter Expansion
@cindex parameter expansion
@@ -1954,11 +1980,11 @@ interpreted as part of its name.
If the first character of @var{parameter} is an exclamation point (!),
and @var{parameter} is not a @var{nameref},
it introduces a level of variable indirection.
Bash uses the value of the variable formed from the rest of
@var{parameter} as the name of the variable; this variable is then
expanded and that value is used in the rest of the substitution, rather
than the value of @var{parameter} itself.
it introduces a level of indirection.
Bash uses the value formed by expanding the rest of
@var{parameter} as the new @var{parameter}; this is then
expanded and that value is used in the rest of the expansion, rather
than the expansion of the original @var{parameter}.
This is known as @code{indirect expansion}.
The value is subject to tilde expansion,
parameter expansion, command substitution, and arithmetic expansion.
@@ -4353,8 +4379,8 @@ parent.
@item mapfile
@btindex mapfile
@example
mapfile [-d @var{delim}] [-n @var{count}] [-O @var{origin}] [-s @var{count}] [-t] [-u @var{fd}]
[-C @var{callback}] [-c @var{quantum}] [@var{array}]
mapfile [-d @var{delim}] [-n @var{count}] [-O @var{origin}] [-s @var{count}]
[-t] [-u @var{fd}] [-C @var{callback}] [-c @var{quantum}] [@var{array}]
@end example
Read lines from the standard input into the indexed array variable @var{array},
@@ -4561,8 +4587,8 @@ Read input from file descriptor @var{fd}.
@item readarray
@btindex readarray
@example
readarray [-d @var{delim}] [-n @var{count}] [-O @var{origin}] [-s @var{count}] [-t] [-u @var{fd}]
[-C @var{callback}] [-c @var{quantum}] [@var{array}]
readarray [-d @var{delim}] [-n @var{count}] [-O @var{origin}] [-s @var{count}]
[-t] [-u @var{fd}] [-C @var{callback}] [-c @var{quantum}] [@var{array}]
@end example
Read lines from the standard input into the indexed array variable @var{array},
@@ -5617,7 +5643,8 @@ The shell sets @code{BASH_ARGC} only when in extended debugging mode
(see @ref{The Shopt Builtin}
for a description of the @code{extdebug} option to the @code{shopt}
builtin).
Setting @code{extdebug} after the shell has started to execute a script
Setting @code{extdebug} after the shell has started to execute a script,
or referencing this variable when @code{extdebug} is not set,
may result in inconsistent values.
@item BASH_ARGV
@@ -5630,7 +5657,8 @@ The shell sets @code{BASH_ARGV} only when in extended debugging mode
(see @ref{The Shopt Builtin}
for a description of the @code{extdebug} option to the @code{shopt}
builtin).
Setting @code{extdebug} after the shell has started to execute a script
Setting @code{extdebug} after the shell has started to execute a script,
or referencing this variable when @code{extdebug} is not set,
may result in inconsistent values.
@item BASH_ARGV0
@@ -6073,6 +6101,11 @@ input to the shell. This is only in effect for interactive shells.
The name of the Readline initialization file, overriding the default
of @file{~/.inputrc}.
@item INSIDE_EMACS
If Bash finds this variable in the environment when the shell
starts, it assumes that the shell is running in an Emacs shell buffer
and may disable line editing depending on the value of @env{TERM}.
@item LANG
Used to determine the locale category for any category not specifically
selected with a variable starting with @code{LC_}.
@@ -6156,7 +6189,9 @@ as if the command
@code{set -o posix}
@end example
@noindent
had been executed.
had been executed.
When the shell enters @sc{posix} mode, it sets this variable if it was
not already set.
@item PPID
The process @sc{id} of the shell's parent process. This variable
@@ -6330,9 +6365,12 @@ This chapter describes features unique to Bash.
@section Invoking Bash
@example
bash [long-opt] [-ir] [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] [@var{argument} @dots{}]
bash [long-opt] [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] -c @var{string} [@var{argument} @dots{}]
bash [long-opt] -s [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] [@var{argument} @dots{}]
bash [long-opt] [-ir] [-abefhkmnptuvxdBCDHP] [-o @var{option}]
[-O @var{shopt_option}] [@var{argument} @dots{}]
bash [long-opt] [-abefhkmnptuvxdBCDHP] [-o @var{option}]
[-O @var{shopt_option}] -c @var{string} [@var{argument} @dots{}]
bash [long-opt] -s [-abefhkmnptuvxdBCDHP] [-o @var{option}]
[-O @var{shopt_option}] [@var{argument} @dots{}]
@end example
All of the single-character options used with the @code{set} builtin
@@ -7421,7 +7459,7 @@ shell session.
After the string is decoded, it is expanded via
parameter expansion, command substitution, arithmetic
expansion, and quote removal, subject to the value of the
@code{promptvars} shell option (@pxref{Bash Builtins}).
@code{promptvars} shell option (@pxref{The Shopt Builtin}).
@node The Restricted Shell
@section The Restricted Shell
@@ -7492,6 +7530,9 @@ startup files.
The following list is what's changed when `@sc{posix} mode' is in effect:
@enumerate
@item
Bash ensures that the @env{POSIXLY_CORRECT} variable is set.
@item
When a command in the hash table no longer exists, Bash will re-search
@env{$PATH} to find the new location. This is also available with