dmbcs/i-bash
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Imported from ../bash-2.01.tar.gz.

Browse source
This commit is contained in:
Jari Aalto 1997-06-05 14:59:13 +00:00
commit d166f04881
304 changed files with 14702 additions and 13012 deletions
Download patch file Download diff file Expand all files Collapse all files

262
doc/FAQ
View file

@ -1,4 +1,4 @@
This is the Bash FAQ, version 2.1, for Bash version 2.0.
This is the Bash FAQ, version 2.5, for Bash version 2.01.
This document contains a set of frequently-asked questions concerning
Bash, the GNU Bourne-Again Shell. Bash is a freely-available command
@ -24,77 +24,78 @@ Section A: The Basics
2) What's the latest version?
3) Where can I get it?
4) On what machines will bash run?
5) How can I build bash with gcc?
6) How can I make bash my login shell?
7) I just changed my login shell to bash, and now I can't FTP into my
5) Will bash run on operating systems other than Unix?
6) How can I build bash with gcc?
7) How can I make bash my login shell?
8) I just changed my login shell to bash, and now I can't FTP into my
machine. Why not?
8) What's the `POSIX 1003.2 standard'?
9) What is the bash `posix mode'?
9) What's the `POSIX 1003.2 standard'?
10) What is the bash `posix mode'?
Section B: The latest version
10) What's new in version 2.0?
11) Are there any user-visible incompatibilities between bash-2.0 and
11) What's new in version 2.01?
12) Are there any user-visible incompatibilities between bash-2.01 and
bash-1.14.7?
Section C: Differences from other Unix shells
12) How does bash differ from sh, the Bourne shell?
13) How does bash differ from the Korn shell, version ksh88?
14) Which new features in ksh-93 are not in bash, and which are?
13) How does bash differ from sh, the Bourne shell?
14) How does bash differ from the Korn shell, version ksh88?
15) Which new features in ksh-93 are not in bash, and which are?
Section D: Why does bash do some things differently than other Unix shells?
15) Why does bash run a different version of `command' than
16) Why does bash run a different version of `command' than
`which command' says it will?
16) Why doesn't bash treat brace expansions exactly like csh?
17) Why doesn't bash have csh variable modifiers?
18) How can I make my csh aliases work when I convert to bash?
19) How can I pipe standard output and standard error from one command to
17) Why doesn't bash treat brace expansions exactly like csh?
18) Why doesn't bash have csh variable modifiers?
19) How can I make my csh aliases work when I convert to bash?
20) How can I pipe standard output and standard error from one command to
another, like csh does with `|&'?
20) Now that I've converted from ksh to bash, are there equivalents to
21) Now that I've converted from ksh to bash, are there equivalents to
ksh features like autoloaded functions and the `whence' command?
Section E: How can I get bash to do certain things, and why does bash do
things the way it does?
21) Why is the bash builtin `test' slightly different from /bin/test?
22) Why does bash sometimes say `Broken pipe'?
23) How can I get bash to read and display eight-bit characters?
24) How do I write a function `x' to replace builtin command `x', but
22) Why is the bash builtin `test' slightly different from /bin/test?
23) Why does bash sometimes say `Broken pipe'?
24) How can I get bash to read and display eight-bit characters?
25) How do I write a function `x' to replace builtin command `x', but
still invoke the command from within the function?
25) When I have terminal escape sequences in my prompt, why does bash
26) When I have terminal escape sequences in my prompt, why does bash
wrap lines at the wrong column?
26) How can I find the value of a shell variable whose name is the value
27) How can I find the value of a shell variable whose name is the value
of another shell variable?
27) If I pipe the output of a command into `read variable', why doesn't
28) If I pipe the output of a command into `read variable', why doesn't
the output show up in $variable when the read command finishes?
28) I have a bunch of shell scripts that use backslash-escaped characters
29) I have a bunch of shell scripts that use backslash-escaped characters
in arguments to `echo'. Bash doesn't interpret these characters. Why
not, and how can I make it understand them?
29) Why doesn't a while or for loop get suspended when I type ^Z?
30) How can I make the bash `time' reserved word print timing output that
30) Why doesn't a while or for loop get suspended when I type ^Z?
31) How can I make the bash `time' reserved word print timing output that
looks like the output from my system's /usr/bin/time?
Section F: Things to watch out for on certain Unix versions
31) Why can't I use command line editing in my `cmdtool'?
32) I built bash on Solaris 2. Why do globbing expansions and filename
32) Why can't I use command line editing in my `cmdtool'?
33) I built bash on Solaris 2. Why do globbing expansions and filename
completion chop off the first few characters of each filename?
33) Why does bash dump core after I interrupt username completion or
34) Why does bash dump core after I interrupt username completion or
`~user' tilde expansion on a machine running NIS?
34) I'm running SVR4.2. Why is the line erased every time I type `@'?
35) Why does bash report syntax errors when my C News scripts use a
35) I'm running SVR4.2. Why is the line erased every time I type `@'?
36) Why does bash report syntax errors when my C News scripts use a
redirection before a subshell command?
Section G: Where do I go from here?
36) How do I report bugs in bash, and where should I look for fixes and
37) How do I report bugs in bash, and where should I look for fixes and
advice?
37) What kind of bash documentation is there?
38) What's coming in future versions?
39) What's on the bash `wish list'?
40) When will the next release appear?
38) What kind of bash documentation is there?
39) What's coming in future versions?
40) What's on the bash `wish list'?
41) When will the next release appear?
----------
Section A: The Basics
@ -119,7 +120,7 @@ of Case Western Reserve University.
2) What's the latest version?
The latest version is 2.0, first made available on December 23, 1996.
The latest version is 2.01, first made available on June 6, 1997.
3) Where can I get it?
@ -127,15 +128,15 @@ Bash is the GNU project's shell, and so is available from the
master GNU archive site, prep.ai.mit.edu, and its mirrors. The
latest version is also available for FTP from slc2.ins.cwru.edu,
the maintainer's machine. The following URLs tell how to get
version 2.0:
version 2.01:
ftp://prep.ai.mit.edu/pub/gnu/bash-2.0.tar.gz
ftp://slc2.ins.cwru.edu/pub/dist/bash-2.0.tar.gz
ftp://prep.ai.mit.edu/pub/gnu/bash-2.01.tar.gz
ftp://slc2.ins.cwru.edu/pub/dist/bash-2.01.tar.gz
Formatted versions of the documentation are available with the URLs:
ftp://prep.ai.mit.edu/pub/gnu/bash-doc-2.0.tar.gz
ftp://slc2.ins.cwru.edu/pub/dist/bash-doc-2.0.tar.gz
ftp://prep.ai.mit.edu/pub/gnu/bash-doc-2.01.tar.gz
ftp://slc2.ins.cwru.edu/pub/dist/bash-doc-2.01.tar.gz
4) On what machines will bash run?
@ -147,12 +148,49 @@ itself accordingly, using a script created by GNU autoconf.
More information appears in the file `INSTALL' in the distribution.
5) How can I build bash with gcc?
5) Will bash run on operating systems other than Unix?
Configuration specifics for Unix-like systems such as QNX and
LynxOS are included in the distribution. Previous versions of
bash have been ported to Minix, but I don't believe anyone has
built bash-2.x on Minix yet.
Bash has been ported to versions of Windows implementing the Win32
programming interface. This includes Windows 95 and Windows NT.
The port was done by Cygnus Solutions as part of their GNU-Win32
project. For more information about the project, look at the URL
http://www.cygnus.com/misc/gnu-win32
Cygnus has ported bash-1.14.7. Maybe someday they (or I) will port
bash-2.01 (or later) to the GNU-Win32 environment.
D. J. Delorie has ported bash-1.14.7 to run under MS-DOS, as part of
the DJGPP project. For more information on the project, see
http://www.delorie.com/djgpp/
I picked up a binary of bash-1.14.7 that is purported to work with
the DJGPP V2 environment from
ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh1147b.zip
The corresponding source is
ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh1147s.zip
A port of bash-1.12 is available for OS/2 from
ftp://hobbes.nmsu.edu/os2/unix/bash_112.zip
I haven't looked at it.
6) How can I build bash with gcc?
Bash configures to use gcc by default if it is available. Read the
file INSTALL in the distribution for more information.
6) How can I make bash my login shell?
7) How can I make bash my login shell?
Some machines let you use `chsh' to change your login shell. Other
systems use `passwd -s'. If one of these works for you, that's all
@ -182,18 +220,23 @@ like
to ensure that bash is exec'd only when the csh is interactive.
If your login shell is sh or ksh, you have to do two things. First, add
a line similar to the above to ~/.profile:
If your login shell is sh or ksh, you have to do two things.
[ -f /usr/gnu/bin/bash ] && exec /usr/gnu/bin/bash --login
Next, create an empty file in your home directory named `.bash_profile'.
First, create an empty file in your home directory named `.bash_profile'.
The existence of this file will prevent the exec'd bash from trying to
read ~/.profile, and re-execing itself over and over again. ~/.bash_profile
is the file bash tries to read initialization commands from when it is
invoked as a login shell.
is the first file bash tries to read initialization commands from when
it is invoked as a login shell.
7) I just changed my login shell to bash, and now I can't FTP into my
Next, add a line similar to the above to ~/.profile:
[ -f /usr/gnu/bin/bash ] && exec /usr/gnu/bin/bash --login
This will cause login shells to replace themselves with bash running as
a login shell. Once you have this working, you can copy your initialization
code from ~/.profile to ~/.bash_profile.
8) I just changed my login shell to bash, and now I can't FTP into my
machine. Why not?
You must add the full pathname to bash to the file /etc/shells. As
@ -203,7 +246,7 @@ this before you can make bash your login shell.
Most versions of ftpd use this file to prohibit `special' users
such as `uucp' and `news' from using FTP.
8) What's the `POSIX 1003.2 standard'?
9) What's the `POSIX 1003.2 standard'?
POSIX is a name originally coined by Richard Stallman for a
family of open system standards based on UNIX. There are a
@ -238,7 +281,7 @@ line editing. Only vi-style line editing commands have been
standardized; emacs editing commands were left out due to
objections.
9) What is the bash `posix mode'?
10) What is the bash `posix mode'?
Although bash is an implementation of the POSIX.2 shell
specification, there are areas where the bash default behavior
@ -255,10 +298,16 @@ Reference Manual.
Section B: The latest version
10) What's new in version 2.0?
11) What's new in version 2.01?
This version contains extensive changes and new features. Here's a
short list:
Bash-2.01 contains only a few new features.
new `GROUPS' builtin array variable containing the user's group list
new bindable readline commands: history-and-alias-expand-line and
alias-expand-line
Bash-2.0 contains extensive changes and new features from bash-1.14.7.
Here's a short list:
new `time' reserved word to time pipelines, shell builtins, and
shell functions
@ -295,15 +344,15 @@ grammar tighter and smaller (66 reduce-reduce conflicts gone)
lots of code now smaller and faster
test suite greatly expanded
11) Are there any user-visible incompatibilities between bash-2.0 and
12) Are there any user-visible incompatibilities between bash-2.01 and
bash-1.14.7?
There are a few incompatibilities between version 1.14.7 and version 2.0.
They are detailed in the file COMPAT in the bash-2.0 distribution.
There are a few incompatibilities between version 1.14.7 and version 2.01.
They are detailed in the file COMPAT in the bash-2.01 distribution.
Section C: Differences from other Unix shells
12) How does bash differ from sh, the Bourne shell?
13) How does bash differ from sh, the Bourne shell?
This is a non-comprehensive list of features that differentiate bash
from the SVR4.2 shell. The bash manual page explains these more
@ -370,7 +419,6 @@ Things sh has that bash does not:
includes `stop' builtin (bash can use alias stop='kill -s STOP')
`newgrp' builtin
turns on job control if called as `jsh'
ulimit attempts to set both soft & hard limits if -S/-H not given
$TIMEOUT (like bash $TMOUT)
`^' is a synonym for `|'
new SVR4.2 sh builtins: mldmode, priv
@ -386,11 +434,12 @@ Implementation differences:
sh does not allow traps on SIGALRM or SIGCHLD
bash allows multiple option arguments when invoked (e.g. -x -v);
sh allows only a single option argument (`sh -x -v' attempts
to open a file named `-v', and, on SunOS 4.1.4, dumps core)
to open a file named `-v', and, on SunOS 4.1.4, dumps core.
On Solaris 2, sh goes into an infinite loop.)
sh exits a script if any builtin fails; bash exits only if one of
the POSIX.2 `special' builtins fails
13) How does bash differ from the Korn shell, version ksh88?
14) How does bash differ from the Korn shell, version ksh88?
Things bash has or uses that ksh88 does not:
long invocation options
@ -438,15 +487,14 @@ Things ksh88 has or uses that bash does not:
Implementation differences:
ksh runs last command of a pipeline in parent shell context
ksh ulimit sets hard and soft limits by default
bash has brace expansion by default (ksh88 compile-time option)
bash has fixed startup file for all interactive shells; ksh reads $ENV
bash has exported functions
bash command search finds functions before builtins
14) Which new features in ksh-93 are not in bash, and which are?
15) Which new features in ksh-93 are not in bash, and which are?
New things in ksh-93 not in bash-2.0:
New things in ksh-93 not in bash-2.01:
associative arrays
floating point arithmetic
++, --, comma arithmetic operators
@ -466,11 +514,10 @@ New things in ksh-93 not in bash-2.0:
`fc' has been renamed to `hist'
read -t/-d
`.' can execute shell functions
ENV processed only for interactive shells
New things in ksh-93 present in bash-2.0:
New things in ksh-93 present in bash-2.01:
?: arithmetic operator
expansions: ${!param}, ${param:len[:offset]}, ${param/pat[/str]}
expansions: ${!param}, ${param:offset[:len]}, ${param/pat[/str]}
compound array assignment
the `!' reserved word
loadable builtins -- but ksh uses `builtin' while bash uses `enable'
@ -488,10 +535,11 @@ New things in ksh-93 present in bash-2.0:
unalias -a
command and arithmetic substitution performed on PS1, PS4, and ENV
command name completion
ENV processed only for interactive shells
Section D: Why does bash do some things differently than other Unix shells?
15) Why does bash run a different version of `command' than
16) Why does bash run a different version of `command' than
`which command' says it will?
`which' is actually a csh script that assumes you're running csh.
@ -500,7 +548,7 @@ those to determine which `command' will be invoked. Since bash
doesn't use any of those startup files, there's a good chance
that your bash environment differs from your csh environment.
16) Why doesn't bash treat brace expansions exactly like csh?
17) Why doesn't bash treat brace expansions exactly like csh?
The only difference between bash and csh brace expansion is that
bash requires a brace expression to contain at least one unquoted
@ -511,7 +559,7 @@ compatibility.
Bash, ksh, zsh, and pd-ksh all implement brace expansion this way.
17) Why doesn't bash have csh variable modifiers?
18) Why doesn't bash have csh variable modifiers?
Posix has specified a more powerful, albeit somewhat more cryptic,
mechanism cribbed from ksh, and bash implements it.
@ -566,7 +614,7 @@ Given
$b:e ${b##*.} xxx
18) How can I make my csh aliases work when I convert to bash?
19) How can I make my csh aliases work when I convert to bash?
Bash uses a different syntax to support aliases than csh does.
The details can be found in the documentation. We have provided
@ -609,7 +657,7 @@ simply `cshtobash' to convert your normal interactive
environment, or as `cshtobash ~/.login' to convert your login
environment.
19) How can I pipe standard output and standard error from one command to
20) How can I pipe standard output and standard error from one command to
another, like csh does with `|&'?
Use
@ -619,7 +667,7 @@ The key is to remember that piping is performed before redirection, so
file descriptor 1 points to the pipe when it is duplicated onto file
descriptor 2.
20) Now that I've converted from ksh to bash, are there equivalents to
21) Now that I've converted from ksh to bash, are there equivalents to
ksh features like autoloaded functions and the `whence' command?
There are features in ksh-88 that do not have direct bash equivalents.
@ -642,7 +690,7 @@ read var?prompt read -p prompt var
Section E: How can I get bash to do certain things, and why does bash do
things the way it does?
21) Why is the bash builtin `test' slightly different from /bin/test?
22) Why is the bash builtin `test' slightly different from /bin/test?
The specific example used here is [ ! x -o x ], which is false.
@ -671,7 +719,7 @@ of the 3 Arg case.
As you can see, the test becomes (not (x or x)), which is false.
22) Why does bash sometimes say `Broken pipe'?
23) Why does bash sometimes say `Broken pipe'?
If a sequence of commands appears in a pipeline, and one of the
reading commands finishes before the writer has finished, the
@ -686,7 +734,7 @@ will try to write on a pipe without a reader. In that case, bash
will print `Broken pipe' to stderr when ps is killed by a
SIGPIPE.
23) How can I get bash to read and display eight-bit characters?
24) How can I get bash to read and display eight-bit characters?
This is a process requiring several steps.
@ -720,7 +768,7 @@ this. These variables can be set in your .inputrc or using the bash
The `set' commands between the single quotes may also be placed
in ~/.inputrc.
24) How do I write a function `x' to replace builtin command `x', but
25) How do I write a function `x' to replace builtin command `x', but
still invoke the command from within the function?
This is why the `command' and `builtin' builtins exist. The
@ -741,7 +789,7 @@ something like the following:
This could also be written using `command' instead of `builtin';
the version above is marginally more efficient.
25) When I have terminal escape sequences in my prompt, why does bash
26) When I have terminal escape sequences in my prompt, why does bash
wrap lines at the wrong column?
Readline, the line editing library that bash uses, does not know
@ -757,10 +805,10 @@ characters in the prompt strings take up no screen space.
Use the \[ escape to begin a sequence of non-printing characters,
and the \] escape to signal the end of such a sequence.
26) How can I find the value of a shell variable whose name is the value
27) How can I find the value of a shell variable whose name is the value
of another shell variable?
Bash-2.0 supports this directly. You can use
Bash-2.01 supports this directly. You can use
${!var}
@ -782,13 +830,13 @@ parameter:
The expansion of the quoted portions of this expression will be
deferred until `eval' runs, while the `$#' will be expanded
before `eval' is executed. In bash-2.0,
before `eval' is executed. In bash-2.01,
echo ${!#}
does the same thing.
27) If I pipe the output of a command into `read variable', why doesn't
28) If I pipe the output of a command into `read variable', why doesn't
the output show up in $variable when the read command finishes?
This has to do with the parent-child relationship between Unix
@ -844,7 +892,7 @@ this.
This is the general approach -- in most cases you will not need to
set $IFS to a different value.
28) I have a bunch of shell scripts that use backslash-escaped characters
29) I have a bunch of shell scripts that use backslash-escaped characters
in arguments to `echo'. Bash doesn't interpret these characters. Why
not, and how can I make it understand them?
@ -864,7 +912,7 @@ configure with the --enable-usg-echo-default option to turn this
on. Be aware that this will cause some of the tests run when you
type `make tests' to fail.
29) Why doesn't a while or for loop get suspended when I type ^Z?
30) Why doesn't a while or for loop get suspended when I type ^Z?
This is a consequence of how job control works on Unix. The only
thing that can be suspended is the process group. This is a single
@ -879,7 +927,7 @@ If you want to be able to stop the entire loop, you need to put it
within parentheses, which will force the loop into a subshell that
may be stopped (and subsequently restarted) as a single unit.
30) How can I make the bash `time' reserved word print timing output that
31) How can I make the bash `time' reserved word print timing output that
looks like the output from my system's /usr/bin/time?
The bash command timing code looks for a variable `TIMEFORMAT' and
@ -913,7 +961,7 @@ The ksh format can be emulated with:
Section F: Things to watch out for on certain Unix versions
31) Why can't I use command line editing in my `cmdtool'?
32) Why can't I use command line editing in my `cmdtool'?
The problem is `cmdtool' and bash fighting over the input. When
scrolling is enabled in a cmdtool window, cmdtool puts the tty in
@ -941,7 +989,7 @@ The bash command-line editing should behave better in the new
cmdtool. If this works, you can put the assignment to TERMCAP
in your bashrc file.
32) I built bash on Solaris 2. Why do globbing expansions and filename
33) I built bash on Solaris 2. Why do globbing expansions and filename
completion chop off the first few characters of each filename?
This is the consequence of building bash on SunOS 5 and linking
@ -961,7 +1009,7 @@ If you have installed the Sun C compiler, you may also need to
put /usr/ccs/bin and /opt/SUNWspro/bin into your $PATH before
/usr/ucb.
33) Why does bash dump core after I interrupt username completion or
34) Why does bash dump core after I interrupt username completion or
`~user' tilde expansion on a machine running NIS?
This is a famous and long-standing bug in the SunOS YP (sorry, NIS)
@ -984,7 +1032,7 @@ times; that's probably why this has never been fixed. You can
run configure with the `--without-gnu-malloc' option to use
the C library malloc and avoid the problem.
34) I'm running SVR4.2. Why is the line erased every time I type `@'?
35) I'm running SVR4.2. Why is the line erased every time I type `@'?
The `@' character is the default `line kill' character in most
versions of System V, including SVR4.2. You can change this
@ -995,7 +1043,7 @@ change the line kill character to control-u, type
where the `^' and `U' can be two separate characters.
35) Why does bash report syntax errors when my C News scripts use a
36) Why does bash report syntax errors when my C News scripts use a
redirection before a subshell command?
The actual command in question is something like
@ -1007,7 +1055,7 @@ is, in fact, a syntax error. Redirections may only precede `simple
commands'. A subshell construct such as the above is one of the shell's
`compound commands'. A redirection may only follow a compound command.
The file CWRU/sh-redir-hack in the bash-2.0 distribution is an
The file CWRU/sh-redir-hack in the bash-2.01 distribution is an
(unofficial) patch to parse.y that will modify the grammar to
support this construct. It will not apply with `patch'; you must
modify parse.y by hand. Note that if you apply this, you must
@ -1016,7 +1064,7 @@ number of reduce/reduce conflicts into the shell grammar.
Section G: Where do I go from here?
36) How do I report bugs in bash, and where should I look for fixes and
37) How do I report bugs in bash, and where should I look for fixes and
advice?
Use the `bashbug' script to report bugs. It is built and
@ -1034,7 +1082,7 @@ and problems also take place there.
To reach the bash maintainers directly, send mail to
bash-maintainers@prep.ai.mit.edu.
37) What kind of bash documentation is there?
38) What kind of bash documentation is there?
First, look in the doc directory in the bash distribution. It should
contain at least the following files:
@ -1056,19 +1104,23 @@ slc2.ins.cwru.edu in the `pub/bash' directory.
Cameron Newham and Bill Rosenblatt have written a book on bash, published
by O'Reilly and Associates. The book is based on Bill Rosenblatt's Korn
Shell book. The title is ``Learning the Bash Shell''. The ISBN number is
1-56592-147-X. Look for it in fine bookstores near you. This book covers
bash-1.14, but has an appendix describing some of the new features in
bash-2.0.
Shell book. The title is ``Learning the Bash Shell'', and the ISBN number
is 1-56592-147-X. Look for it in fine bookstores near you. This book
covers bash-1.14, but has an appendix describing some of the new features
in bash-2.0. There are rumors of a second edition of this book, describing
bash-2.0 (and 2.01). I do not know what ORA's publication schedule for
this edition is.
38) What's coming in future versions?
39) What's coming in future versions?
These are features I plan to include in a future version of bash.
POSIX.2-style globbing character classes ([:alpha:], [:alnum:], etc.)
a bash debugger (an incomplete, untested version is included with bash-2.0)
POSIX.2-style globbing equivalence classes
POSIX.2-style globbing collating symbols
a bash debugger (a minimally-tested version is included with bash-2.01)
39) What's on the bash `wish list' for future versions?
40) What's on the bash `wish list' for future versions?
These are features that may or may not appear in a future version of bash.
@ -1084,7 +1136,7 @@ timeouts for the `read' builtin
the ksh-93 ${!prefix*} and ${!prefix@} operators
arithmetic ++ and -- prefix and postfix operators
40) When will the next release appear?
41) When will the next release appear?
The next version will appear sometime in 1997. Never make predictions.

14
doc/Makefile.in
View file

@ -148,14 +148,20 @@ installdirs:
install: info installdirs
-$(INSTALL_DATA) $(srcdir)/bash.1 $(man1dir)/bash.${man1ext}
-$(INSTALL_DATA) $(srcdir)/bashbug.1 $(man1dir)/bashbug.${man1ext}
-$(INSTALL_DATA) $(srcdir)/readline.3 $(man3dir)/readline.${man3ext}
-$(INSTALL_DATA) $(srcdir)/bashref.info $(infodir)/bash.info
# uncomment the next line to install the readline man page
# -$(INSTALL_DATA) $(srcdir)/readline.3 $(man3dir)/readline.${man3ext}
# uncomment the next line to install the builtins man page
# $(INSTALL_DATA) builtins.1 $(man1dir)/bash_builtins.${man1ext}
-$(INSTALL_DATA) $(srcdir)/bashref.info $(infodir)/bash.info
# run install-info if it is present to update the info directory
if $(SHELL) -c 'install-info --version' >/dev/null 2>&1; then \
install-info --dir-file=$(infodir)/dir $(infodir)/bash.info; \
else true; fi
uninstall:
$(RM) $(man1dir)/bash.${man1ext} $(man1dir)/bashbug.${man1ext}
$(RM) $(man3dir)/readline.${man3ext} $(infodir)/bash.info
-$(RM) $(man1dir)/bash.${man1ext} $(man1dir)/bashbug.${man1ext}
-$(RM) $(man3dir)/readline.${man3ext}
$(RM) $(infodir)/bash.info
# for use by chet
inst: bashref.texi

87
doc/bash.1
View file

@ -6,11 +6,11 @@
.\" Case Western Reserve University
.\" chet@ins.CWRU.Edu
.\"
.\" Last Change: Mon Nov 25 15:36:20 EST 1996
.\" Last Change: Mon May 19 12:45:24 EDT 1997
.\"
.\" bash_builtins, strip all but Built-Ins section
.if \n(zZ=1 .ig zZ
.TH BASH 1 "1996 Nov 25" GNU
.TH BASH 1 "1997 May 19" GNU
.\"
.\" There's some problem with having a `@'
.\" in a tagged paragraph with the BSD man macros.
@ -256,8 +256,9 @@ section.
.PP
When
.B bash
is invoked as a login shell, it first reads and executes commands
from the file \fI/etc/profile\fP, if that file exists.
is invoked as an interactive login shell, it first reads and
executes commands from the file \fI/etc/profile\fP, if that
file exists.
After reading that file, it looks for \fI~/.bash_profile\fP,
\fI~/.bash_login\fP, and \fI~/.profile\fP, in that order, and reads
and executes commands from the first one that exists and is readable.
@ -623,7 +624,7 @@ is the exit status of the last command executed in
.IR list ,
or zero if no commands were executed.
.TP
\fBcase\fP \fIword\fP \fBin\fP [ \fIpattern\fP [ \fB|\fP \fIpattern\fP ] \
\fBcase\fP \fIword\fP \fBin\fP [ ( \fIpattern\fP [ \fB|\fP \fIpattern\fP ] \
... ) \fIlist\fP ;; ] ... \fBesac\fP
A \fBcase\fP command first expands \fIword\fP, and tries to match
it against each \fIpattern\fP in turn, using the same matching rules
@ -902,7 +903,11 @@ is the first character of the value of the
variable. If
.SM
.B IFS
is null or unset, the parameters are separated by spaces.
is unset, the parameters are separated by spaces.
If
.SM
.B IFS
is null, the parameters are joined without intervening separators.
.TP
.B @
Expands to the positional parameters, starting from one. When the
@ -999,6 +1004,10 @@ Expands to the user ID of the current user, initialized at shell startup.
Expands to the effective user ID of the current user, initialized at
shell startup.
.TP
.B GROUPS
An array variable containing the list of groups of which the current
user is a member.
.TP
.B BASH
Expands to the full file name used to invoke this instance of
.BR bash .
@ -1221,14 +1230,14 @@ specified by the
command. A sample value is
``.:~:/usr''.
.TP
.B ENV
.B BASH_ENV
If this parameter is set when \fBbash\fP is executing a shell script,
its value is interpreted as a filename containing commands to
initialize the shell, as in
.IR .bashrc .
The value of
.SM
.B ENV
.B BASH_ENV
is subjected to parameter expansion, command substitution, and arithmetic
expansion before being interpreted as a file name.
.SM
@ -3130,7 +3139,7 @@ below).
.SH READLINE
This is the library that handles reading input when using an interactive
shell, unless the
.B \-noediting
.B \-\-noediting
option is given at shell invocation.
By default, the line editing commands are similar to those of emacs.
A vi-style line editing interface is also available.
@ -3668,11 +3677,22 @@ word expansions. See
below for a description of history expansion.
.TP
.B history\-expand\-line (M\-^)
Perform history expansion on the current line. See
Perform history expansion on the current line.
See
.SM
.B HISTORY EXPANSION
below for a description of history expansion.
.TP
.B alias\-expand\-line
Perform alias expansion on the current line.
See
.SM
.B ALIASES
above for a description of alias expansion.
.TP
.B history\-and\-alias\-expand\-line
Perform history and alias expansion on the current line.
.TP
.B insert\-last\-argument (M\-.\^, M\-_\^)
A synonym for \fByank\-last\-arg\fP.
.TP
@ -3794,9 +3814,18 @@ Add this digit to the argument already accumulating, or start a new
argument. M\-\- starts a negative argument.
.TP
.B universal\-argument
Each time this is executed, the argument count is multiplied by four.
This is another way to specify an argument.
If this command is followed by one or more digits, optionally with a
leading minus sign, those digits define the argument.
If the command is followed by digits, executing
.B universal\-argument
again ends the numeric argument, but is otherwise ignored.
As a special case, if this command is immediately followed by a
character that is neither a digit or minus sign, the argument count
for the next command is multiplied by four.
The argument count is initially one, so executing this function the
first time makes the argument count four.
first time makes the argument count four, a second time makes the
argument count sixteen, and so on.
.PD
.SS Completing
.PP
@ -3980,7 +4009,7 @@ Display version information about the current instance of
.PD
.SH HISTORY
When the
.B -o history
.B \-o history
option to the
.B set
builtin is enabled, the shell provides access to the
@ -5494,12 +5523,15 @@ Arguments, if supplied, have the following meanings:
\fB+\fP\fIn\fP
Rotates the stack so that the \fIn\fPth directory
(counting from the left of the list shown by
.BR dirs )
.BR dirs ,
starting with zero)
is at the top.
.TP
\fB\-\fP\fIn\fP
Rotates the stack so that the \fIn\fPth directory
(counting from the right) is at the top.
(counting from the right of the list shown by
.BR dirs ,
starting with zero) is at the top.
.TP
.B \-n
Suppresses the normal change of directory when adding directories
@ -6006,7 +6038,7 @@ The errors checked for are transposed characters,
a missing character, and one character too many.
If a correction is found, the corrected file name is printed,
and the command proceeds.
This option is enabled by default, but is only used by interactive shells.
This option is only used by interactive shells.
.TP 8
.B checkhash
If set, \fBbash\fP checks that a command found in the hash
@ -6303,7 +6335,7 @@ may be positive or negative integers.
Print the accumulated user and system times for the shell and
for processes run from the shell. The return status is 0.
.TP
\fBtrap\fP [\fB\-lp\fP] [\fIarg\fP] [\fIsigspec\fP]
\fBtrap\fP [\fB\-lp\fP] [\fIarg\fP] [\fIsigspec\fP ...]
The command
.I arg
is to be read and executed when the shell receives
@ -6315,11 +6347,12 @@ is absent or
.BR \- ,
all specified signals are
reset to their original values (the values they had
upon entrance to the shell). If
upon entrance to the shell).
If
.I arg
is the null string this
signal is ignored by the shell and by the
commands it invokes.
is the null string the signal specified by each
.I sigspec
is ignored by the shell and by the commands it invokes.
If
.I arg
is
@ -6333,16 +6366,18 @@ only
is given,
.B trap
prints the list of commands associated with each signal number.
Each
.I sigspec
is either
a signal name defined in <\fIsignal.h\fP>, or a signal number. If
a signal name defined in <\fIsignal.h\fP>, or a signal number.
If a
.I sigspec
is
.SM
.B EXIT
(0) the command
.I arg
is executed on exit from the shell. If
is executed on exit from the shell. If a
.I sigspec
is
.SM
@ -6359,7 +6394,8 @@ option causes the shell to print a list of signal names and
their corresponding numbers.
Signals ignored upon entry to the shell cannot be trapped or reset.
Trapped signals are reset to their original values in a child
process when it is created. The return status is false if any
process when it is created.
The return status is false if any
.I sigspec
is invalid; otherwise
.B trap
@ -6723,8 +6759,7 @@ that you have.
Once you have determined that a bug actually exists, use the
.I bashbug
command to submit a bug report.
If you have a fix, you are welcome to mail that
as well!
If you have a fix, you are encouraged to mail that as well!
Suggestions and `philosophical' bug reports may be mailed
to \fPbug-bash\fP@\fIprep.ai.MIT.Edu\fP or posted to the Usenet
newsgroup

626
doc/bashref.info
View file

@ -4,9 +4,9 @@ input file ./bashref.texi.
This text is a brief description of the features that are present in
the Bash shell.
This is Edition 2.0, last updated 25 November 1996,
This is Edition 2.0, last updated 19 May 1997,
of `The GNU Bash Reference Manual',
for `Bash', Version 2.0.
for `Bash', Version 2.01.
Copyright (C) 1991, 1993, 1996 Free Software Foundation, Inc.
@ -33,8 +33,8 @@ Bash Features
This text is a brief description of the features that are present in
the Bash shell.
This is Edition 2.0, last updated 25 November 1996, of `The GNU Bash
Reference Manual', for `Bash', Version 2.0.
This is Edition 2.0, last updated 19 May 1997, of `The GNU Bash
Reference Manual', for `Bash', Version 2.01.
Copyright (C) 1991, 1993, 1996 Free Software Foundation, Inc.
@ -205,8 +205,8 @@ Definitions
descended from it, that are all in the same process group.
`job control'
A mechanism by which users can selectively start and stop execution
of processes.
A mechanism by which users can selectively stop (suspend) and
restart (resume) execution of processes.
`metacharacter'
A character that, when unquoted, separates words. A metacharacter
@ -612,7 +612,7 @@ Conditional Constructs
`case'
The syntax of the `case' command is:
`case WORD in [PATTERN [| PATTERN]...) COMMANDS ;;]... esac'
`case WORD in [ ( PATTERN [| PATTERN]...) COMMANDS ;;]... esac'
Selectively execute COMMANDS based upon WORD matching PATTERN.
The `|' is used to separate multiple patterns.
@ -634,7 +634,7 @@ Conditional Constructs
(( EXPRESSION ))
The EXPRESSION is evaluated according to the rules described below
((*note Arithmetic Evaluation::.). If the value of the expression
(*note Arithmetic Evaluation::.). If the value of the expression
is non-zero, the return status is 0; otherwise the return status
is 1. This is exactly equivalent to
let "EXPRESSION"
@ -673,8 +673,8 @@ the list may be redirected to a single stream.
difference between these two constructs due to historical reasons. The
braces are `reserved words', so they must be separated from the LIST by
`blank's. The parentheses are `operators', and are recognized as
separate tokens by the shell even if they are not separated from `list'
by whitespace.
separate tokens by the shell even if they are not separated from the
LIST by whitespace.
The exit status of both of these constructs is the exit status of
LIST.
@ -701,7 +701,7 @@ status of the last command executed in the body.
When a function is executed, the arguments to the function become
the positional parameters during its execution (*note Positional
Parameters::.). The special parameter `#' that gives the number of
Parameters::.). The special parameter `#' that expands to the number of
positional parameters is updated to reflect the change. Positional
parameter `0' is unchanged.
@ -783,8 +783,9 @@ only be referenced; assignment to them is not allowed.
with the value of each parameter separated by the first character
of the `IFS' special variable. That is, `"$*"' is equivalent to
`"$1C$2C..."', where C is the first character of the value of the
`IFS' variable. If `IFS' is null or unset, the parameters are
separated by spaces.
`IFS' variable. If `IFS' is unset, the parameters are separated
by spaces. If `IFS' is null, the parameters are joined without
intervening separators.
`@'
Expands to the positional parameters, starting from one. When the
@ -880,7 +881,7 @@ parameter, variable, and arithemtic expansion and command substitution.
Only brace expansion, word splitting, and filename expansion can
change the number of words of the expansion; other expansions expand a
single word to a single word. The only exceptions to this are the
expansions of `"$@"' (*note Special Parameters::.) and `"${[@]}"'
expansions of `"$@"' (*note Special Parameters::.) and `"${NAME[@]}"'
(*note Arrays::.).
After all expansions, `quote removal' (*note Quote Removal::.) is
@ -907,9 +908,9 @@ name.
If the first character of PARAMETER is an exclamation point, a level
of variable indirection is introduced. Bash uses the value of the
variable formed from the rest of PARAMETER as the name of the variable;
this variable is then expanded and that value used in the rest of the
substitution, rather than the value of PARAMETER itself. This is known
as `indirect expansion'.
this variable is then expanded and that value is used in the rest of
the substitution, rather than the value of PARAMETER itself. This is
known as `indirect expansion'.
In each of the cases below, WORD is subject to tilde expansion,
parameter expansion, command substitution, and arithmetic expansion.
@ -1654,20 +1655,21 @@ standard.
children.
`trap'
trap [-lp] [ARG] [SIGSPEC]
trap [-lp] [ARG] [SIGSPEC ...]
The commands in ARG are to be read and executed when the shell
receives signal SIGSPEC. If ARG is absent or equal to `-', all
specified signals are reset to the values they had when the shell
was started. If ARG is the null string, then SIGSPEC is ignored by
the shell and commands it invokes. If ARG is `-p', the shell
displays the trap commands associated with each SIGSPEC. If no
arguments are supplied, or only `-p' is given, `trap' prints the
list of commands associated with each signal number. SIGSPEC is
either a signal name such as `SIGINT' or a signal number. If
SIGSPEC is `0' or `EXIT', ARG is executed when the shell exits.
If SIGSPEC is `DEBUG', the command ARG is executed after every
simple command. The `-l' option causes the shell to print a list
of signal names and their corresponding numbers.
was started. If ARG is the null string, then the signal specified
by each SIGSPEC is ignored by the shell and commands it invokes.
If ARG is `-p', the shell displays the trap commands associated
with each SIGSPEC. If no arguments are supplied, or only `-p' is
given, `trap' prints the list of commands associated with each
signal number. Each SIGSPEC is either a signal name such as
`SIGINT' (with or without the `SIG' prefix) or a signal number.
If a SIGSPEC is `0' or `EXIT', ARG is executed when the shell
exits. If a SIGSPEC is `DEBUG', the command ARG is executed after
every simple command. The `-l' option causes the shell to print a
list of signal names and their corresponding numbers.
Signals ignored upon entry to the shell cannot be trapped or reset.
Trapped signals are reset to their original values in a child
@ -1826,7 +1828,7 @@ translation of the characters between the double quotes. The `-D' and
`--dump-strings' invocation options list the translatable strings found
in a script (*note Locale Translation::.).
The expansion `${var:'LENGTH`[:'OFFSET`]}', which expands to the
The expansion `${var:'OFFSET`[:'LENGTH`]}', which expands to the
substring of `var''s value of length LENGTH, optionally beginning at
OFFSET, is present (*note Shell Parameter Expansion::.).
@ -1842,10 +1844,10 @@ Parameter Expansion::.).
Bash has process substitution (*note Process Substitution::.).
Bash automatically assigns variables that provide information about
the current user (`UID' and `EUID'), the current host (`HOSTTYPE',
`OSTYPE', `MACHTYPE', and `HOSTNAME'), and the instance of Bash that is
running (`BASH', `BASH_VERSION', and `BASH_VERSINFO'. *Note Bash
Variables::, for details.
the current user (`UID', `EUID', and `GROUPS'), the current host
(`HOSTTYPE', `OSTYPE', `MACHTYPE', and `HOSTNAME'), and the instance of
Bash that is running (`BASH', `BASH_VERSION', and `BASH_VERSINFO'.
*Note Bash Variables::, for details.
The `IFS' variable is used to split only the results of expansion,
not all words (*note Word Splitting::.). This closes a longstanding
@ -1858,9 +1860,9 @@ shell security hole.
`local' builtin, and thus useful recursive functions may be written.
Variable assignments preceding commands affect only that command,
even builtins and functions. In `sh', all variable assignments
preceding commands are global unless the command is executed from the
file system.
even builtins and functions (*note Environment::.). In `sh', all
variable assignments preceding commands are global unless the command
is executed from the file system.
Bash performs filename expansion on filenames specified as operands
to output redirection operators.
@ -1932,16 +1934,17 @@ shell input, a `-n' option to remove various variable attributes, and
`name=value' arguments to set variable attributes and values
simultaneously.
The Bash `cd' and `pwd' builtins each take `-L' and `-P' builtins to
switch between logical and physical modes.
The Bash `cd' and `pwd' builtins (*note Bourne Shell Builtins::.)
each take `-L' and `-P' builtins to switch between logical and physical
modes.
The Bash `type' builtin is more extensive and gives more information
about the names it finds.
about the names it finds (*note Bash Builtins::.).
Bash implements a `csh'-like directory stack, and provides the
`pushd', `popd', and `dirs' builtins to manipulate it. Bash also makes
the directory stack visible as the value of the `DIRSTACK' shell
variable.
`pushd', `popd', and `dirs' builtins to manipulate it (*note C Shell
Builtins::.). Bash also makes the directory stack visible as the value
of the `DIRSTACK' shell variable.
The Bash restricted mode is more useful (*note The Restricted
Shell::.); the SVR4.2 shell restricted mode is too limited.
@ -1979,10 +1982,10 @@ from many of the limitations of the SVR4.2 shell. For instance:
`SIGSEGV' blocked (e.g., by using the `system()' C library
function call), the shell misbehaves badly.
* In a questionable attempt at security, the SVR4.2 shell will alter
its real and effective UID and GID if they are less than some
threshold value, commonly 100. This can lead to unexpected
results.
* In a questionable attempt at security, the SVR4.2 shell, when
invoked without the `-p' option, will alter its real and effective
UID and GID if they are less than some magic threshold value,
commonly 100. This can lead to unexpected results.
* The SVR4.2 shell does not allow users to trap `SIGALRM' or
`SIGCHLD'.
@ -1999,7 +2002,7 @@ from many of the limitations of the SVR4.2 shell. For instance:
* The SVR4.2 shell exits a script if any builtin fails; Bash exits a
script only if one of the POSIX.2 special builtins fails, and only
for certain failures, as enumerated in the `POSIX.2' standard.
for certain failures, as enumerated in the POSIX.2 standard.
* The SVR4.2 shell behaves differently when invoked as `jsh' (it
turns on job control).
@ -2108,13 +2111,13 @@ to `csh'.
`+N'
Brings the Nth directory (counting from the left of the list
printed by `dirs') to the top of the list by rotating the
stack.
printed by `dirs', starting with zero) to the top of the list
by rotating the stack.
`-N'
Brings the Nth directory (counting from the right of the list
printed by `dirs') to the top of the list by rotating the
stack.
printed by `dirs', starting with zero) to the top of the list
by rotating the stack.
`-n'
Suppresses the normal change of directory when adding
@ -2288,10 +2291,10 @@ saved in the variable `REPLY'.
completes.
Bash also has adopted command timing from the Korn shell. If the
`time' reserved word precedes a pipeline or simple command, timing
statistics for the pipeline are displayed when it completes. The
statistics currently consist of elapsed (wall-clock) time and user and
system time consumed by the command's execution.
`time' reserved word precedes a pipeline, which may consist of a single
command, timing statistics for the pipeline are displayed when it
completes. The statistics currently consist of elapsed (wall-clock)
time and user and system time consumed by the command's execution.
The use of `time' as a reserved word permits the timing of shell
builtins, shell functions, and pipelines. An external `time' command
@ -2389,12 +2392,6 @@ Korn Shell Variables
The line number in the script or shell function currently
executing.
`ENV'
If this variable is set when Bash is invoked to execute a shell
script, its value is expanded and used as the name of a startup
file to read before executing the script. *Note Bash Startup
Files::.
`FCEDIT'
The editor used as a default by the `fc' builtin command.
@ -2609,17 +2606,18 @@ File: bashref.info, Node: Bash Startup Files, Next: Is This Shell Interactive?
Bash Startup Files
==================
This section describs how bash executes its startup files. If any
of the files exist but cannot be read, bash reports an error. Tildes
This section describs how Bash executes its startup files. If any
of the files exist but cannot be read, Bash reports an error. Tildes
are expanded in file names as described above under Tilde Expansion
(*note Tilde Expansion::.).
When Bash is invoked as a login shell, it first reads and executes
commands from the file `/etc/profile', if that file exists. After
reading that file, it looks for `~/.bash_profile', `~/.bash_login', and
`~/.profile', in that order, and reads and executes commands from the
first one that exists and is readable. The `--noprofile' option may be
used when the shell is started to inhibit this behavior.
When Bash is invoked as an interactive login shell, it first reads
and executes commands from the file `/etc/profile', if that file exists.
After reading that file, it looks for `~/.bash_profile',
`~/.bash_login', and `~/.profile', in that order, and reads and
executes commands from the first one that exists and is readable. The
`--noprofile' option may be used when the shell is started to inhibit
this behavior.
When a login shell exits, Bash reads and executes commands from the
file `~/.bash_logout', if it exists.
@ -2667,7 +2665,7 @@ are read.
line option, it follows the POSIX standard for startup files. In this
mode, the `ENV' variable is expanded and commands are read and executed
from the file whose name is the expanded value. No other startup files
are read. This is done by both interactive and non-interactive shells.
are read. This is done by interactive shells only.
Bash attempts to determine when it is being run by the remote shell
daemon, usually `rshd'. If Bash determines it is being run by rshd, it
@ -2699,6 +2697,14 @@ Thus:
echo This shell is interactive
fi
Alternatively, you may test the value of the `-' special parameter.
It contains `i' when the shell is interactive. For example:
case "$-" in
*i*) echo This shell is interactive ;;
*) echo This shell is not interactive ;;
esac

File: bashref.info, Node: Bash Builtins, Next: The Set Builtin, Prev: Is This Shell Interactive?, Up: Bash Features
@ -2764,9 +2770,9 @@ been extended in Bash.
`builtin'
builtin [SHELL-BUILTIN [ARGS]]
Run a shell builtin. This is useful when you wish to rename a
shell builtin to be a function, but need the functionality of the
builtin within the function itself.
Run a shell builtin. This is useful when you wish to define a
shell function with the same name as a shell builtin, but need the
functionality of the builtin within the function itself.
`command'
command [-pVv] COMMAND [ARGS ...]
@ -2974,7 +2980,7 @@ been extended in Bash.
are transposed characters, a missing character, and a
character too many. If a correction is found, the corrected
path is printed, and the command proceeds. This option is
enabled by default, but is only used by interactive shells.
only used by interactive shells.
`checkhash'
If this is set, Bash checks that a command found in the hash
@ -3018,7 +3024,8 @@ been extended in Bash.
`hostcomplete'
If set, and Readline is being used, Bash will attempt to
perform hostname completion when a word beginning with `@' is
being completed (*note Commands For Completion::.).
being completed (*note Commands For Completion::.). This
option is enabled by default.
`interactive_comments'
Allow a word beginning with `#' to cause that word and all
@ -3249,10 +3256,10 @@ The Set Builtin
same as `-x'.
`-p'
Turn on privileged mode. In this mode, the `$ENV' file is
not processed, and shell functions are not inherited from the
environment. This is enabled automatically on startup if the
effective user (group) id is not equal to the real user
Turn on privileged mode. In this mode, the `$BASH_ENV' file
is not processed, and shell functions are not inherited from
the environment. This is enabled automatically on startup if
the effective user (group) id is not equal to the real user
(group) id. Turning this option off causes the effective user
and group ids to be set to the real user and group ids.
@ -3484,6 +3491,12 @@ Bash Variables
These variables are set or used by Bash, but other shells do not
normally treat them specially.
`BASH_ENV'
If this variable is set when Bash is invoked to execute a shell
script, its value is expanded and used as the name of a startup
file to read before executing the script. *Note Bash Startup
Files::.
`TIMEFORMAT'
The value of this parameter is used as a format string specifying
how the timing information for pipelines prefixed with the `time'
@ -3518,9 +3531,9 @@ normally treat them specially.
fraction is included.
If this variable is not set, bash acts as if it had the value
`$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS''. If the value is null,
no timing information is displayed. A trailing newline is added
when the format string is displayed.
`$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS''.
If the value is null, no timing information is displayed. A
trailing newline is added when the format string is displayed.
`HISTCONTROL'
Set to a value of `ignorespace', it means don't enter lines which
@ -3603,6 +3616,10 @@ normally treat them specially.
`EUID'
The numeric effective user id of the current user.
`GROUPS'
An array variable containing the list of groups of which the
current user is a member.
`PPID'
The process id of the shell's parent process.
@ -3691,8 +3708,8 @@ normally treat them specially.
`SHLVL'
Incremented by one each time a new instance of Bash is started.
This is intended to be an account of how deeply your Bash shells
are nested.
This is intended to be a count of how deeply your Bash shells are
nested.
`OPTERR'
If set to the value 1, Bash displays error messages generated by
@ -3706,9 +3723,13 @@ normally treat them specially.
This variable overrides the value of `LANG' and any other `LC_'
variable specifying a locale category.
`LC_COLLATE'
This variable determines the collation order used when sorting the
results of filename expansion (*note Filename Expansion::.).
`LC_MESSAGES'
This variable determines the locale used to translate double-quoted
strings preceded by a `$'.
strings preceded by a `$' (*note Locale Translation::.).
`IGNOREEOF'
Controls the action of the shell on receipt of an `EOF' character
@ -4110,6 +4131,9 @@ specified by POSIX.2 in areas where the Bash default differs.
20. Assignment statements preceding POSIX.2 `special' builtins persist
in the shell environment after the builtin completes.
21. The `export' and `readonly' builtin commands display their output
in the format required by POSIX.2.
There is other POSIX.2 behavior that Bash does not implement.
Specifically:
@ -4264,10 +4288,11 @@ Job Control Builtins
kill [-s SIGSPEC] [-n SIGNUM] [-SIGSPEC] JOBSPEC
kill -l [SIGSPEC]
Send a signal specified by SIGSPEC or SIGNUM to the process named
by JOBSPEC. SIGSPEC is either a signal name such as `SIGINT' or a
signal number; SIGNUM is a signal number. If SIGSPEC and SIGNUM
are not present, `SIGTERM' is used. The `-l' option lists the
signal names, or the signal name corresponding to SIGSPEC.
by JOBSPEC. SIGSPEC is either a signal name such as `SIGINT'
(with or without the `SIG' prefix) or a signal number; SIGNUM is a
signal number. If SIGSPEC and SIGNUM are not present, `SIGTERM'
is used. The `-l' option lists the signal names, or the signal
name corresponding to SIGSPEC.
`wait'
wait [JOBSPEC|PID]
@ -4304,12 +4329,12 @@ Job Control Variables
This variable controls how the shell interacts with the user and
job control. If this variable exists then single word simple
commands without redirects are treated as candidates for resumption
of an existing job. There is no ambiguity allowed; if you have
more than one job beginning with the string that you have typed,
then the most recently accessed job will be selected. The name of
a stopped job, in this context, is the command line used to start
it. If this variable is set to the value `exact', the string
supplied must match the name of a stopped job exactly; if set to
of an existing job. There is no ambiguity allowed; if there is
more than one job beginning with the string typed, then the most
recently accessed job will be selected. The name of a stopped
job, in this context, is the command line used to start it. If
this variable is set to the value `exact', the string supplied
must match the name of a stopped job exactly; if set to
`substring', the string supplied needs to match a substring of the
name of a stopped job. The `substring' value provides
functionality analogous to the `%?' job ID (*note Job Control
@ -5094,31 +5119,31 @@ binding, variable assignment, and conditional syntax.
#
# Arrow keys in keypad mode
#
#"\M-OD" backward-char
#"\M-OC" forward-char
#"\M-OA" previous-history
#"\M-OB" next-history
#"\M-OD": backward-char
#"\M-OC": forward-char
#"\M-OA": previous-history
#"\M-OB": next-history
#
# Arrow keys in ANSI mode
#
"\M-[D" backward-char
"\M-[C" forward-char
"\M-[A" previous-history
"\M-[B" next-history
"\M-[D": backward-char
"\M-[C": forward-char
"\M-[A": previous-history
"\M-[B": next-history
#
# Arrow keys in 8 bit keypad mode
#
#"\M-\C-OD" backward-char
#"\M-\C-OC" forward-char
#"\M-\C-OA" previous-history
#"\M-\C-OB" next-history
#"\M-\C-OD": backward-char
#"\M-\C-OC": forward-char
#"\M-\C-OA": previous-history
#"\M-\C-OB": next-history
#
# Arrow keys in 8 bit ANSI mode
#
#"\M-\C-[D" backward-char
#"\M-\C-[C" forward-char
#"\M-\C-[A" previous-history
#"\M-\C-[B" next-history
#"\M-\C-[D": backward-char
#"\M-\C-[C": forward-char
#"\M-\C-[A": previous-history
#"\M-\C-[B": next-history
C-q: quoted-insert
@ -5410,10 +5435,17 @@ Specifying Numeric Arguments
argument. M- starts a negative argument.
`universal-argument ()'
Each time this is executed, the argument count is multiplied by
four. The argument count is initially one, so executing this
function the first time makes the argument count four. By
default, this is not bound to a key.
This is another way to specify an argument. If this command is
followed by one or more digits, optionally with a leading minus
sign, those digits define the argument. If the command is
followed by digits, executing `universal-argument' again ends the
numeric argument, but is otherwise ignored. As a special case, if
this command is immediately followed by a character that is
neither a digit or minus sign, the argument count for the next
command is multiplied by four. The argument count is initially
one, so executing this function the first time makes the argument
count four, a second time makes the argument count sixteen, and so
on. By default, this is not bound to a key.

File: bashref.info, Node: Commands For Completion, Next: Keyboard Macros, Prev: Numeric Arguments, Up: Bindable Readline Commands
@ -5606,6 +5638,12 @@ Some Miscellaneous Commands
`history-expand-line (M-^)'
Perform history expansion on the current line.
`alias-expand-line'
Perform alias expansion on the current line (*note Aliases::.).
`history-and-alias-expand-line'
Perform history and alias expansion on the current line.
`insert-last-argument (M-., M-_)'
A synonym for `yank-last-arg'.
@ -5652,7 +5690,7 @@ OS/2, Windows 95, and Windows NT.
* Menu:
* Basic Installation:: Generic installation instructions.
* Basic Installation:: Installation instructions.
* Compilers and Options:: How to set special options for various
systems.
@ -5679,7 +5717,7 @@ File: bashref.info, Node: Basic Installation, Next: Compilers and Options, Up
Basic Installation
==================
These are generic installation instructions for Bash.
These are installation instructions for Bash.
The `configure' shell script attempts to guess correct values for
various system-dependent variables used during compilation. It uses
@ -5702,7 +5740,15 @@ they can be considered for the next release.
The file `configure.in' is used to create `configure' by a program
called Autoconf. You only need `configure.in' if you want to change it
or regenerate `configure' using a newer version of Autoconf. If you do
this, make sure you are using Autoconf version 2.9 or newer.
this, make sure you are using Autoconf version 2.10 or newer.
If you need to change `configure.in' or regenerate `configure', you
will need to create two files: `_distribution' and `_patchlevel'.
`_distribution' should contain the major and minor version numbers of
the Bash distribution, for example `2.01'. `_patchlevel' should
contain the patch level of the Bash distribution, `0' for example. The
script `support/mkconffiles' has been provided to automate the creation
of these files.
The simplest way to compile Bash is:
@ -5880,21 +5926,27 @@ configure Bash without a feature that is enabled by default, use
Here is a complete list of the `--enable-' and `--with-' options
that the Bash `configure' recognizes.
`--with-gnu-malloc'
Use the GNU version of `malloc' in `lib/malloc/malloc.c'. This is
not the same `malloc' that appears in GNU libc, but an older
version derived from the 4.2 BSD `malloc'. This `malloc' is very
fast, but wastes a lot of space. This option is enabled by
default. The `NOTES' file contains a list of systems for which
this should be turned off.
`--with-afs'
Define if you are using the Andrew File System from Transarc.
`--with-curses'
Use the curses library instead of the termcap library. This should
be supplied if your system has an inadequate or incomplete termcap
database.
`--with-glibc-malloc'
Use the GNU libc version of `malloc' in `lib/malloc/gmalloc.c'.
This is somewhat slower than the default `malloc', but wastes
considerably less space.
`--with-afs'
Define if you are using the Andrew File System from Transarc.
`--with-gnu-malloc'
Use the GNU version of `malloc' in `lib/malloc/malloc.c'. This is
not the same `malloc' that appears in GNU libc, but an older
version derived from the 4.2 BSD `malloc'. This `malloc' is very
fast, but wastes a lot of space. This option is enabled by
default. The `NOTES' file contains a list of systems for which
this should be turned off, and `configure' disables this option
automatically for a number of systems.
`--with-purify'
Define this to use the Purify memory allocation checker from Pure
@ -5912,32 +5964,48 @@ enabled using `enable-FEATURE'.
`usg-echo-default' are enabled by default, unless the operating system
does not provide the necessary support.
`--enable-job-control'
This enables job control features, if the OS supports them.
`--enable-alias'
Allow alias expansion and include the `alias' and `unalias'
builtins.
`--enable-readline'
Include support for command-line editing and history with the Bash
version of the Readline library.
`--enable-history'
Include command history and the `fc' and `history' builtin
commands.
`--enable-array-variables'
Include support for one-dimensional array shell variables.
`--enable-bang-history'
Include support for `csh'-like history substitution.
`--enable-brace-expansion'
Include `csh'-like brace expansion ( `b{a,b}c' ==> `bac bbc' ).
`--enable-command-timing'
Include support for recognizing `time' as a reserved word and for
displaying timing statistics for the pipeline following `time'.
This allows pipelines as well as shell builtins and functions to
be timed.
`--enable-directory-stack'
Include support for a `csh'-like directory stack and the `pushd',
`popd', and `dirs' builtins.
`--enable-restricted'
Include support for a "restricted shell". If this is enabled,
Bash, when called as `rbash', enters a restricted mode. See *Note
The Restricted Shell::, for a description of restricted mode.
`--enable-disabled-builtins'
Allow builtin commands to be invoked via `builtin xxx' even after
`xxx' has been disabled using `enable -n xxx'. See *Note Bash
Builtins::, for details of the `builtin' and `enable' builtin
commands.
`--enable-dparen-arithmetic'
Include support for the `ksh' `((...))' command.
`--enable-help-builtin'
Include the `help' builtin, which displays help on shell builtins
and variables.
`--enable-history'
Include command history and the `fc' and `history' builtin
commands.
`--enable-job-control'
This enables job control features, if the OS supports them.
`--enable-process-substitution'
This enables process substitution (*note Process Substitution::.)
@ -5948,35 +6016,19 @@ does not provide the necessary support.
characters in the `$PS1', `$PS2', `$PS3', and `$PS4' prompt
strings.
`--enable-readline'
Include support for command-line editing and history with the Bash
version of the Readline library.
`--enable-restricted'
Include support for a "restricted shell". If this is enabled,
Bash, when called as `rbash', enters a restricted mode. See *Note
The Restricted Shell::, for a description of restricted mode.
`--enable-select'
Include the `ksh' `select' builtin, which allows the generation of
simple menus.
`--enable-help-builtin'
Include the `help' builtin, which displays help on shell builtins
and variables.
`--enable-array-variables'
Include support for one-dimensional array shell variables.
`--enable-dparen-arithmetic'
Include support for the `ksh' `((...))' command.
`--enable-brace-expansion'
Include `csh'-like brace expansion ( `b{a,b}c' ==> `bac bbc' ).
`--enable-disabled-builtins'
Allow builtin commands to be invoked via `builtin xxx' even after
`xxx' has been disabled using `enable -n xxx'. See *Note Bash
Builtins::, for details of the `builtin' and `enable' builtin
commands.
`--enable-command-timing'
Include support for recognizing `time' as a reserved word and for
displaying timing statistics for the pipeline following `time'.
This allows pipelines as well as shell builtins and functions to
be timed.
`--enable-usg-echo-default'
Make the `echo' builtin expand backslash-escaped characters by
default, without requiring the `-e' option. This makes the Bash
@ -6000,7 +6052,7 @@ of Bash that you have.
Once you have determined that a bug actually exists, use the
`bashbug' command to submit a bug report. If you have a fix, you are
welcome to mail that as well! Suggestions and `philosophical' bug
encouraged to mail that as well! Suggestions and `philosophical' bug
reports may be mailed to `bug-bash@prep.ai.MIT.Edu' or posted to the
Usenet newsgroup `gnu.bash.bug'.
@ -6132,6 +6184,7 @@ Parameter and Variable Index
* _: Special Parameters.
* auto_resume: Job Control Variables.
* BASH: Bash Variables.
* BASH_ENV: Bash Variables.
* BASH_VERSINFO: Bash Variables.
* BASH_VERSION: Bash Variables.
* bell-style: Readline Init File Syntax.
@ -6143,12 +6196,12 @@ Parameter and Variable Index
* disable-completion: Readline Init File Syntax.
* editing-mode: Readline Init File Syntax.
* enable-keypad: Readline Init File Syntax.
* ENV: Korn Shell Variables.
* EUID: Bash Variables.
* expand-tilde: Readline Init File Syntax.
* FCEDIT: Korn Shell Variables.
* FIGNORE: Bash Variables.
* GLOBIGNORE: Bash Variables.
* GROUPS: Bash Variables.
* histchars: Bash Variables.
* HISTCMD: Bash Variables.
* HISTCONTROL: Bash Variables.
@ -6169,6 +6222,7 @@ Parameter and Variable Index
* keymap: Readline Init File Syntax.
* LANG: Bash Variables.
* LC_ALL: Bash Variables.
* LC_COLLATE: Bash Variables.
* LC_MESSAGES: Bash Variables.
* LINENO: Korn Shell Variables.
* MACHTYPE: Bash Variables.
@ -6391,123 +6445,123 @@ Concept Index

Tag Table:
Node: Top1009
Node: Introduction3117
Node: What is Bash?3342
Node: What is a shell?4426
Node: Definitions6307
Node: Basic Shell Features8947
Node: Shell Syntax10468
Node: Shell Operation10758
Node: Quoting11992
Node: Escape Character13027
Node: Single Quotes13458
Node: Double Quotes13787
Node: ANSI-C Quoting14483
Node: Locale Translation15215
Node: Comments15636
Node: Simple Commands16160
Node: Pipelines16749
Node: Lists17820
Node: Looping Constructs19095
Node: Conditional Constructs20272
Node: Command Grouping22337
Node: Shell Functions23721
Node: Shell Parameters25489
Node: Positional Parameters26812
Node: Special Parameters27506
Node: Shell Expansions29998
Node: Shell Parameter Expansion31998
Node: Command Substitution38003
Node: Process Substitution39003
Node: Word Splitting39909
Node: Filename Expansion41361
Node: Quote Removal43727
Node: Redirections44013
Node: Executing Commands49754
Node: Command Search and Execution50209
Node: Environment51943
Node: Exit Status53579
Node: Signals54596
Node: Shell Scripts55807
Node: Bourne Shell Features57676
Node: Bourne Shell Builtins58346
Node: Bourne Shell Variables66619
Node: Other Bourne Shell Features68156
Node: Major Differences From The Bourne Shell68913
Node: Csh Features79111
Node: Brace Expansion80029
Node: Tilde Expansion81584
Node: C Shell Builtins82216
Node: C Shell Variables86732
Node: Korn Shell Features87140
Node: Korn Shell Constructs87868
Node: Korn Shell Builtins89562
Node: Korn Shell Variables91720
Node: Aliases93505
Node: Alias Builtins95969
Node: Bash Features96585
Node: Invoking Bash97576
Node: Bash Startup Files101441
Node: Is This Shell Interactive?105024
Node: Bash Builtins105755
Node: The Set Builtin121569
Node: Bash Conditional Expressions126939
Node: Bash Variables131590
Node: Shell Arithmetic141103
Node: Arithmetic Evaluation141571
Node: Arithmetic Expansion143601
Node: Arithmetic Builtins144405
Node: Arrays144876
Node: Printing a Prompt147903
Node: The Restricted Shell149501
Node: Bash POSIX Mode150731
Node: Job Control154303
Node: Job Control Basics154768
Node: Job Control Builtins158911
Node: Job Control Variables161794
Node: Using History Interactively162955
Node: Bash History Facilities163544
Node: History Interaction165942
Node: Event Designators168504
Node: Word Designators169427
Node: Modifiers170676
Node: Command Line Editing171993
Node: Introduction and Notation172653
Node: Readline Interaction173661
Node: Readline Bare Essentials174849
Node: Readline Movement Commands176378
Node: Readline Killing Commands177268
Node: Readline Arguments178970
Node: Searching179943
Node: Readline Init File181579
Node: Readline Init File Syntax182635
Node: Conditional Init Constructs190424
Node: Sample Init File192705
Node: Bindable Readline Commands195722
Node: Commands For Moving196472
Node: Commands For History197319
Node: Commands For Text199992
Node: Commands For Killing201734
Node: Numeric Arguments203760
Node: Commands For Completion204386
Node: Keyboard Macros207348
Node: Miscellaneous Commands207906
Node: Readline vi Mode211937
Node: Installing Bash212813
Node: Basic Installation213890
Node: Compilers and Options216389
Node: Compiling For Multiple Architectures217123
Node: Installation Names218780
Node: Specifying the System Type219502
Node: Sharing Defaults220213
Node: Operation Controls220878
Node: Optional Features221783
Node: Reporting Bugs226408
Node: Builtin Index227485
Node: Reserved Word Index230898
Node: Variable Index232206
Node: Function Index237285
Node: Concept Index241643
Node: Top1005
Node: Introduction3109
Node: What is Bash?3334
Node: What is a shell?4418
Node: Definitions6299
Node: Basic Shell Features8960
Node: Shell Syntax10481
Node: Shell Operation10771
Node: Quoting12005
Node: Escape Character13040
Node: Single Quotes13471
Node: Double Quotes13800
Node: ANSI-C Quoting14496
Node: Locale Translation15228
Node: Comments15649
Node: Simple Commands16173
Node: Pipelines16762
Node: Lists17833
Node: Looping Constructs19108
Node: Conditional Constructs20285
Node: Command Grouping22352
Node: Shell Functions23738
Node: Shell Parameters25511
Node: Positional Parameters26834
Node: Special Parameters27528
Node: Shell Expansions30094
Node: Shell Parameter Expansion32098
Node: Command Substitution38106
Node: Process Substitution39106
Node: Word Splitting40012
Node: Filename Expansion41464
Node: Quote Removal43830
Node: Redirections44116
Node: Executing Commands49857
Node: Command Search and Execution50312
Node: Environment52046
Node: Exit Status53682
Node: Signals54699
Node: Shell Scripts55910
Node: Bourne Shell Features57779
Node: Bourne Shell Builtins58449
Node: Bourne Shell Variables66803
Node: Other Bourne Shell Features68340
Node: Major Differences From The Bourne Shell69097
Node: Csh Features79457
Node: Brace Expansion80375
Node: Tilde Expansion81930
Node: C Shell Builtins82562
Node: C Shell Variables87118
Node: Korn Shell Features87526
Node: Korn Shell Constructs88254
Node: Korn Shell Builtins89969
Node: Korn Shell Variables92127
Node: Aliases93686
Node: Alias Builtins96150
Node: Bash Features96766
Node: Invoking Bash97757
Node: Bash Startup Files101622
Node: Is This Shell Interactive?105197
Node: Bash Builtins106180
Node: The Set Builtin122035
Node: Bash Conditional Expressions127410
Node: Bash Variables132061
Node: Shell Arithmetic142095
Node: Arithmetic Evaluation142563
Node: Arithmetic Expansion144593
Node: Arithmetic Builtins145397
Node: Arrays145868
Node: Printing a Prompt148895
Node: The Restricted Shell150493
Node: Bash POSIX Mode151723
Node: Job Control155407
Node: Job Control Basics155872
Node: Job Control Builtins160015
Node: Job Control Variables162938
Node: Using History Interactively164085
Node: Bash History Facilities164674
Node: History Interaction167072
Node: Event Designators169634
Node: Word Designators170557
Node: Modifiers171806
Node: Command Line Editing173123
Node: Introduction and Notation173783
Node: Readline Interaction174791
Node: Readline Bare Essentials175979
Node: Readline Movement Commands177508
Node: Readline Killing Commands178398
Node: Readline Arguments180100
Node: Searching181073
Node: Readline Init File182709
Node: Readline Init File Syntax183765
Node: Conditional Init Constructs191554
Node: Sample Init File193835
Node: Bindable Readline Commands196868
Node: Commands For Moving197618
Node: Commands For History198465
Node: Commands For Text201138
Node: Commands For Killing202880
Node: Numeric Arguments204906
Node: Commands For Completion206030
Node: Keyboard Macros208992
Node: Miscellaneous Commands209550
Node: Readline vi Mode213766
Node: Installing Bash214642
Node: Basic Installation215711
Node: Compilers and Options218636
Node: Compiling For Multiple Architectures219370
Node: Installation Names221027
Node: Specifying the System Type221749
Node: Sharing Defaults222460
Node: Operation Controls223125
Node: Optional Features224030
Node: Reporting Bugs228913
Node: Builtin Index229993
Node: Reserved Word Index233406
Node: Variable Index234714
Node: Function Index239899
Node: Concept Index244257

End Tag Table

290
doc/bashref.texi
View file

@ -5,13 +5,13 @@
@c %**end of header
@ignore
last change: Mon Nov 25 11:47:06 EST 1996
last change: Mon May 19 12:55:22 EDT 1997
@end ignore
@set EDITION 2.0
@set VERSION 2.0
@set UPDATED 25 November 1996
@set UPDATE-MONTH November 1996
@set VERSION 2.01
@set UPDATED 19 May 1997
@set UPDATE-MONTH May 1997
@iftex
@finalout
@ -272,8 +272,8 @@ from it, that are all in the same process group.
@item job control
@cindex job control
A mechanism by which users can selectively start and stop execution
of processes.
A mechanism by which users can selectively stop (suspend) and restart
(resume) execution of processes.
@item metacharacter
@cindex metacharacter
@ -717,7 +717,7 @@ has a non-zero exit status, then execute @var{alternate-consequents}.
The syntax of the @code{case} command is:
@example
@code{case @var{word} in [@var{pattern} [| @var{pattern}]@dots{}) @var{commands} ;;]@dots{} esac}
@code{case @var{word} in [ ( @var{pattern} [| @var{pattern}]@dots{}) @var{commands} ;;]@dots{} esac}
@end example
Selectively execute @var{commands} based upon @var{word} matching
@ -744,7 +744,7 @@ echo " legs."
@end example
The @var{expression} is evaluated according to the rules described
below ((@pxref{Arithmetic Evaluation}).
below (@pxref{Arithmetic Evaluation}).
If the value of the expression is non-zero, the return status is 0;
otherwise the return status is 1. This is exactly equivalent to
@example
@ -794,7 +794,7 @@ between these two constructs due to historical reasons. The braces
are @code{reserved words}, so they must be separated from the @var{list}
by @code{blank}s. The parentheses are @code{operators}, and are
recognized as separate tokens by the shell even if they are not separated
from @code{list} by whitespace.
from the @var{list} by whitespace.
The exit status of both of these constructs is the exit status of
@var{list}.
@ -825,10 +825,9 @@ the exit status of the last command executed in the body.
When a function is executed, the arguments to the
function become the positional parameters
during its execution (@pxref{Positional Parameters}).
The special parameter
@samp{#} that gives the number of positional parameters
is updated to reflect the change. Positional parameter @code{0}
is unchanged.
The special parameter @samp{#} that expands to the number of
positional parameters is updated to reflect the change.
Positional parameter @code{0} is unchanged.
If the builtin command @code{return}
is executed in a function, the function completes and
@ -919,8 +918,11 @@ of the @code{IFS}
special variable. That is, @code{"$*"} is equivalent
to @code{"$1@var{c}$2@var{c}@dots{}"}, where @var{c}
is the first character of the value of the @code{IFS}
variable. If @code{IFS}
is null or unset, the parameters are separated by spaces.
variable.
If @code{IFS} is unset, the parameters are separated by spaces.
If @code{IFS} is null, the parameters are joined without intervening
separators.
@item @@
Expands to the positional parameters, starting from one. When the
@ -1020,7 +1022,7 @@ Only brace expansion, word splitting, and filename expansion
can change the number of words of the expansion; other expansions
expand a single word to a single word.
The only exceptions to this are the expansions of
@code{"$@@"} (@pxref{Special Parameters}) and @code{"$@{[@@]@}"}
@code{"$@@"} (@pxref{Special Parameters}) and @code{"$@{@var{name}[@@]@}"}
(@pxref{Arrays}).
After all expansions, @code{quote removal} (@pxref{Quote Removal})
@ -1050,7 +1052,7 @@ If the first character of @var{parameter} is an exclamation point,
a level of variable indirection is introduced.
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 used in the rest of the substitution, rather
expanded and that value is used in the rest of the substitution, rather
than the value of @var{parameter} itself.
This is known as @code{indirect expansion}.
@ -1953,21 +1955,23 @@ Print out the user and system times used by the shell and its children.
@item trap
@btindex trap
@example
trap [-lp] [@var{arg}] [@var{sigspec}]
trap [-lp] [@var{arg}] [@var{sigspec} @dots{}]
@end example
The commands in @var{arg} are to be read and executed when the
shell receives signal @var{sigspec}. If @var{arg} is absent or
equal to @samp{-}, all specified signals are reset to the values
they had when the shell was started.
If @var{arg} is the null string, then @var{sigspec} is ignored by
the shell and commands it invokes.
If @var{arg} is the null string, then the signal specified by
each @var{sigspec} is ignored by the shell and commands it invokes.
If @var{arg} is @samp{-p}, the shell displays the trap commands
associated with each @var{sigspec}. If no arguments are supplied, or
only @samp{-p} is given, @code{trap} prints the list of commands
associated with each signal number. @var{sigspec} is either a signal
name such as @code{SIGINT} or a signal number. If @var{sigspec} is
@code{0} or @code{EXIT}, @var{arg} is executed when the shell exits.
If @var{sigspec} is @code{DEBUG}, the command @var{arg} is executed
associated with each signal number.
Each @var{sigspec} is either a signal name such as @code{SIGINT} (with
or without the @code{SIG} prefix) or a signal number.
If a @var{sigspec}
is @code{0} or @code{EXIT}, @var{arg} is executed when the shell exits.
If a @var{sigspec} is @code{DEBUG}, the command @var{arg} is executed
after every simple command.
The @samp{-l} option causes the shell to print a list of signal names
and their corresponding numbers.
@ -2136,7 +2140,7 @@ quotes. The @samp{-D} and @samp{--dump-strings} invocation options
list the translatable strings found in a script
(@pxref{Locale Translation}).
The expansion @code{$@{var:}@var{length}@code{[:}@var{offset}@code{]@}},
The expansion @code{$@{var:}@var{offset}@code{[:}@var{length}@code{]@}},
which expands to the substring of @code{var}'s value of length
@var{length}, optionally beginning at @var{offset}, is present
(@pxref{Shell Parameter Expansion}).
@ -2155,7 +2159,7 @@ Bash can expand positional parameters beyond @code{$9} using
Bash has process substitution (@pxref{Process Substitution}).
Bash automatically assigns variables that provide information about the
current user (@code{UID} and @code{EUID}), the current host
current user (@code{UID}, @code{EUID}, and @code{GROUPS}), the current host
(@code{HOSTTYPE}, @code{OSTYPE}, @code{MACHTYPE}, and @code{HOSTNAME}),
and the instance of Bash that is running (@code{BASH},
@code{BASH_VERSION}, and @code{BASH_VERSINFO}. @xref{Bash Variables},
@ -2172,7 +2176,8 @@ Bash functions are permitted to have local variables using the
@code{local} builtin, and thus useful recursive functions may be written.
Variable assignments preceding commands affect only that command, even
builtins and functions. In @code{sh}, all variable assignments
builtins and functions (@pxref{Environment}).
In @code{sh}, all variable assignments
preceding commands are global unless the command is executed from the
file system.
@ -2249,14 +2254,16 @@ used as shell input, a @samp{-n} option to remove various variable
attributes, and @samp{name=value} arguments to set variable attributes
and values simultaneously.
The Bash @code{cd} and @code{pwd} builtins each take @samp{-L} and
@samp{-P} builtins to switch between logical and physical modes.
The Bash @code{cd} and @code{pwd} builtins (@pxref{Bourne Shell Builtins})
each take @samp{-L} and @samp{-P} builtins to switch between logical and
physical modes.
The Bash @code{type} builtin is more extensive and gives more information
about the names it finds.
about the names it finds (@pxref{Bash Builtins}).
Bash implements a @code{csh}-like directory stack, and provides the
@code{pushd}, @code{popd}, and @code{dirs} builtins to manipulate it.
@code{pushd}, @code{popd}, and @code{dirs} builtins to manipulate it
(@pxref{C Shell Builtins}).
Bash also makes the directory stack visible as the value of the
@code{DIRSTACK} shell variable.
@ -2304,10 +2311,11 @@ trapping @code{SIGSEGV}. If the shell is started from a process with
function call), the shell misbehaves badly.
@item
In a questionable attempt at security, the @sc{SVR4.2} shell
will alter its real
In a questionable attempt at security, the @sc{SVR4.2} shell,
when invoked without the @samp{-p} option, will alter its real
and effective @sc{UID} and @sc{GID} if they are less than some
threshold value, commonly 100. This can lead to unexpected results.
magic threshold value, commonly 100.
This can lead to unexpected results.
@item
The @sc{SVR4.2} shell does not allow users to trap @code{SIGALRM} or
@ -2330,7 +2338,7 @@ with a @samp{-}.
@item
The @sc{SVR4.2} shell exits a script if any builtin fails; Bash exits
a script only if one of the @sc{POSIX.2} special builtins fails, and
only for certain failures, as enumerated in the @code{POSIX.2} standard.
only for certain failures, as enumerated in the @sc{POSIX.2} standard.
@item
The @sc{SVR4.2} shell behaves differently when invoked as @code{jsh}
@ -2454,12 +2462,12 @@ arguments, exchanges the top two directories.
@table @code
@item +@var{N}
Brings the @var{N}th directory (counting from the left of the
list printed by @code{dirs}) to the top of the list by rotating
the stack.
list printed by @code{dirs}, starting with zero) to the top of
the list by rotating the stack.
@item -@var{N}
Brings the @var{N}th directory (counting from the right of the
list printed by @code{dirs}) to the top of the list by rotating
the stack.
list printed by @code{dirs}, starting with zero) to the top of
the list by rotating the stack.
@item -n
Suppresses the normal change of directory when adding directories
to the stack, so that only the stack is manipulated.
@ -2644,8 +2652,9 @@ The @var{commands} are executed after each selection until a
point the @code{select} command completes.
Bash also has adopted command timing from the Korn shell. If the
@code{time} reserved word precedes a pipeline or simple command,
timing statistics for the pipeline are displayed when it completes.
@code{time} reserved word precedes a pipeline, which may consist
of a single command, timing statistics for the pipeline are displayed
when it completes.
The statistics currently consist of elapsed (wall-clock) time and
user and system time consumed by the command's execution.
@ -2751,11 +2760,6 @@ not arrive.
@item LINENO
The line number in the script or shell function currently executing.
@item ENV
If this variable is set when Bash is invoked to execute a shell
script, its value is expanded and used as the name of a startup file
to read before executing the script. @xref{Bash Startup Files}.
@item FCEDIT
The editor used as a default by the @code{fc} builtin command.
@ -2992,12 +2996,12 @@ in the script. If no commands are executed, the exit status is 0.
@section Bash Startup Files
@cindex startup files
This section describs how bash executes its startup files.
If any of the files exist but cannot be read, bash reports an error.
This section describs how Bash executes its startup files.
If any of the files exist but cannot be read, Bash reports an error.
Tildes are expanded in file names as described above under
Tilde Expansion (@pxref{Tilde Expansion}).
When Bash is invoked as a login shell, it first reads and
When Bash is invoked as an interactive login shell, it first reads and
executes commands from the file @file{/etc/profile}, if that file exists.
After reading that file, it looks for @file{~/.bash_profile},
@file{~/.bash_login}, and @file{~/.profile}, in that order, and reads
@ -3059,7 +3063,7 @@ for startup files.
In this mode, the @code{ENV} variable is expanded and commands are read
and executed from the file whose name is the expanded value.
No other startup files are read.
This is done by both interactive and non-interactive shells.
This is done by interactive shells only.
Bash attempts to determine when it is being run by the remote shell
daemon, usually @code{rshd}. If Bash determines it is being run by
@ -3093,6 +3097,16 @@ else
fi
@end example
Alternatively, you may test the value of the @samp{-} special parameter.
It contains @code{i} when the shell is interactive. For example:
@example
case "$-" in
*i*) echo This shell is interactive ;;
*) echo This shell is not interactive ;;
esac
@end example
@node Bash Builtins
@section Bash Builtin Commands
@ -3173,9 +3187,9 @@ Remove any current binding for @var{keyseq}
@example
builtin [@var{shell-builtin} [@var{args}]]
@end example
Run a shell builtin. This is useful when you wish to rename a
shell builtin to be a function, but need the functionality of the
builtin within the function itself.
Run a shell builtin. This is useful when you wish to define a
shell function with the same name as a shell builtin, but need the
functionality of the builtin within the function itself.
@item command
@btindex command
@ -3423,7 +3437,7 @@ The errors checked for are transposed characters,
a missing character, and a character too many.
If a correction is found, the corrected path is printed,
and the command proceeds.
This option is enabled by default, but is only used by interactive shells.
This option is only used by interactive shells.
@item checkhash
If this is set, Bash checks that a command found in the hash
@ -3470,7 +3484,8 @@ the Readline editing buffer, allowing further modification.
@item hostcomplete
If set, and Readline is being used, Bash will attempt to perform
hostname completion when a word beginning with @samp{@@} is being
completed (@pxref{Commands For Completion}).
completed (@pxref{Commands For Completion}). This option is enabled
by default.
@item interactive_comments
Allow a word beginning with @samp{#}
@ -3718,7 +3733,7 @@ same as @code{-x}.
@item -p
Turn on privileged mode.
In this mode, the @code{$ENV}
In this mode, the @code{$BASH_ENV}
file is not processed, and shell functions
are not inherited from the environment. This is enabled automatically
on startup if the effective user (group) id is not equal to the real
@ -3962,6 +3977,11 @@ do not normally treat them specially.
@vtable @code
@item BASH_ENV
If this variable is set when Bash is invoked to execute a shell
script, its value is expanded and used as the name of a startup file
to read before executing the script. @xref{Bash Startup Files}.
@item TIMEFORMAT
The value of this parameter is used as a format string specifying
how the timing information for pipelines prefixed with the @code{time}
@ -4002,7 +4022,9 @@ the form @var{MM}m@var{SS}.@var{FF}s.
The value of @var{p} determines whether or not the fraction is included.
If this variable is not set, bash acts as if it had the value
@example
@code{$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'}.
@end example
If the value is null, no timing information is displayed.
A trailing newline is added when the format string is displayed.
@ -4086,6 +4108,10 @@ The numeric real user id of the current user.
@item EUID
The numeric effective user id of the current user.
@item GROUPS
An array variable containing the list of groups of which the current
user is a member.
@item PPID
The process id of the shell's parent process.
@ -4184,7 +4210,7 @@ The value of @code{MACHTYPE}.
@item SHLVL
Incremented by one each time a new instance of Bash is started. This is
intended to be an account of how deeply your Bash shells are nested.
intended to be a count of how deeply your Bash shells are nested.
@item OPTERR
If set to the value 1, Bash displays error messages
@ -4198,9 +4224,13 @@ selected with a variable starting with @code{LC_}.
This variable overrides the value of @code{LANG} and any other
@code{LC_} variable specifying a locale category.
@item LC_COLLATE
This variable determines the collation order used when sorting the
results of filename expansion (@pxref{Filename Expansion}).
@item LC_MESSAGES
This variable determines the locale used to translate double-quoted
strings preceded by a @samp{$}.
strings preceded by a @samp{$} (@pxref{Locale Translation}).
@item IGNOREEOF
Controls the action of the shell on receipt of an @code{EOF} character
@ -4608,14 +4638,6 @@ the POSIX.2 standard, and include things like passing incorrect options,
redirection errors, variable assignment errors for assignments preceding
the command name, and so on.
@ignore
@item
The environment passed to executed commands is not sorted. Neither is
the output of @code{set}. This is not strictly Posix.2 behavior, but
@code{sh} does it this way. @code{ksh} does not. It's not necessary to
sort the environment; no program should rely on it being sorted.
@end ignore
@item
If the @code{cd} builtin finds a directory to change to
using @code{$CDPATH}, the
@ -4641,6 +4663,10 @@ Process substitution is not available.
Assignment statements preceding @sc{POSIX.2} @code{special} builtins
persist in the shell environment after the builtin completes.
@item
The @code{export} and @code{readonly} builtin commands display their
output in the format required by @sc{POSIX.2}.
@end enumerate
There is other @sc{POSIX.2} behavior that Bash does not implement.
@ -4826,9 +4852,10 @@ kill [-s @var{sigspec}] [-n @var{signum}] [-@var{sigspec}] @var{jobspec}
kill -l [@var{sigspec}]
@end example
Send a signal specified by @var{sigspec} or @var{signum} to the process
named by @var{jobspec}. @var{sigspec} is either a signal name such as
@code{SIGINT} or a signal number; @var{signum} is a signal number. If
@var{sigspec} and @var{signum} are not present, @code{SIGTERM} is used.
named by @var{jobspec}.
@var{sigspec} is either a signal name such as @code{SIGINT} (with or without
the @code{SIG} prefix) or a signal number; @var{signum} is a signal number.
If @var{sigspec} and @var{signum} are not present, @code{SIGTERM} is used.
The @samp{-l} option lists the signal names, or the signal name
corresponding to @var{sigspec}.
@ -4878,8 +4905,8 @@ supplied process @sc{ID}s.
This variable controls how the shell interacts with the user and
job control. If this variable exists then single word simple
commands without redirects are treated as candidates for resumption
of an existing job. There is no ambiguity allowed; if you have
more than one job beginning with the string that you have typed, then
of an existing job. There is no ambiguity allowed; if there is
more than one job beginning with the string typed, then
the most recently accessed job will be selected.
The name of a stopped job, in this context, is the command line
used to start it. If this variable is set to the value @samp{exact},
@ -4912,7 +4939,7 @@ version of Unix (and, someday, @sc{GNU}). Other independent ports exist for
@sc{OS/2}, Windows 95, and Windows @sc{NT}.
@menu
* Basic Installation:: Generic installation instructions.
* Basic Installation:: Installation instructions.
* Compilers and Options:: How to set special options for various
systems.
@ -4941,7 +4968,7 @@ version of Unix (and, someday, @sc{GNU}). Other independent ports exist for
@cindex Bash installation
@cindex Bash configuration
These are generic installation instructions for Bash.
These are installation instructions for Bash.
The @code{configure} shell script attempts to guess correct
values for various system-dependent variables used during
@ -4969,8 +4996,17 @@ The file @file{configure.in} is used to create @code{configure}
by a program called Autoconf. You only need
@file{configure.in} if you want to change it or regenerate
@code{configure} using a newer version of Autoconf. If
you do this, make sure you are using Autoconf version 2.9 or
newer.
you do this, make sure you are using Autoconf version 2.10 or
newer.
If you need to change @file{configure.in} or regenerate
@code{configure}, you will need to create two files:
@file{_distribution} and @file{_patchlevel}. @file{_distribution}
should contain the major and minor version numbers of the Bash
distribution, for example @samp{2.01}. @file{_patchlevel} should
contain the patch level of the Bash distribution, @samp{0} for
example. The script @file{support/mkconffiles} has been provided
to automate the creation of these files.
The simplest way to compile Bash is:
@ -5153,6 +5189,19 @@ Here is a complete list of the @samp{--enable-} and
@samp{--with-} options that the Bash @code{configure} recognizes.
@table @code
@item --with-afs
Define if you are using the Andrew File System from Transarc.
@item --with-curses
Use the curses library instead of the termcap library. This should
be supplied if your system has an inadequate or incomplete termcap
database.
@item --with-glibc-malloc
Use the @sc{GNU} libc version of @code{malloc} in
@file{lib/malloc/gmalloc.c}. This is somewhat slower than the
default @code{malloc}, but wastes considerably less space.
@item --with-gnu-malloc
Use the @sc{GNU} version of
@code{malloc} in @file{lib/malloc/malloc.c}. This is not the same
@ -5160,15 +5209,8 @@ Use the @sc{GNU} version of
derived from the 4.2 @sc{BSD} @code{malloc}. This @code{malloc} is
very fast, but wastes a lot of space. This option is enabled by
default. The @file{NOTES} file contains a list of systems for
which this should be turned off.
@item --with-glibc-malloc
Use the @sc{GNU} libc version of @code{malloc} in
@file{lib/malloc/gmalloc.c}. This is somewhat slower than the
default @code{malloc}, but wastes considerably less space.
@item --with-afs
Define if you are using the Andrew File System from Transarc.
which this should be turned off, and @code{configure} disables this
option automatically for a number of systems.
@item --with-purify
Define this to use the Purify memory allocation checker from Pure
@ -5190,32 +5232,48 @@ enabled by default, unless the operating system does not provide the
necessary support.
@table @code
@item --enable-job-control
This enables job control features, if the @sc{OS} supports them.
@item --enable-alias
Allow alias expansion and include the @code{alias} and @code{unalias}
builtins.
@item --enable-readline
Include support for command-line editing and history with the Bash
version of the Readline library.
@item --enable-history
Include command history and the @code{fc} and @code{history}
builtin commands.
@item --enable-array-variables
Include support for one-dimensional array shell variables.
@item --enable-bang-history
Include support for @code{csh}-like history substitution.
@item --enable-brace-expansion
Include @code{csh}-like brace expansion
( @code{b@{a,b@}c} @expansion{} @code{bac bbc} ).
@item --enable-command-timing
Include support for recognizing @code{time} as a reserved word and for
displaying timing statistics for the pipeline following @code{time}. This
allows pipelines as well as shell builtins and functions to be timed.
@item --enable-directory-stack
Include support for a @code{csh}-like directory stack and the
@code{pushd}, @code{popd}, and @code{dirs} builtins.
@item --enable-restricted
Include support for a @dfn{restricted shell}. If this is enabled, Bash,
when called as @code{rbash}, enters a restricted mode. See
@ref{The Restricted Shell}, for a description of restricted mode.
@item --enable-disabled-builtins
Allow builtin commands to be invoked via @samp{builtin xxx}
even after @code{xxx} has been disabled using @samp{enable -n xxx}.
See @ref{Bash Builtins}, for details of the @code{builtin} and
@code{enable} builtin commands.
@item --enable-dparen-arithmetic
Include support for the @code{ksh} @code{((@dots{}))} command.
@item --enable-help-builtin
Include the @code{help} builtin, which displays help on shell builtins and
variables.
@item --enable-history
Include command history and the @code{fc} and @code{history}
builtin commands.
@item --enable-job-control
This enables job control features, if the @sc{OS} supports them.
@item --enable-process-substitution
This enables process substitution (@pxref{Process Substitution}) if
@ -5226,35 +5284,19 @@ Turn on the interpretation of a number of backslash-escaped characters
in the @code{$PS1}, @code{$PS2}, @code{$PS3}, and @code{$PS4} prompt
strings.
@item --enable-readline
Include support for command-line editing and history with the Bash
version of the Readline library.
@item --enable-restricted
Include support for a @dfn{restricted shell}. If this is enabled, Bash,
when called as @code{rbash}, enters a restricted mode. See
@ref{The Restricted Shell}, for a description of restricted mode.
@item --enable-select
Include the @code{ksh} @code{select} builtin, which allows the
generation of simple menus.
@item --enable-help-builtin
Include the @code{help} builtin, which displays help on shell builtins and
variables.
@item --enable-array-variables
Include support for one-dimensional array shell variables.
@item --enable-dparen-arithmetic
Include support for the @code{ksh} @code{((@dots{}))} command.
@item --enable-brace-expansion
Include @code{csh}-like brace expansion
( @code{b@{a,b@}c} @expansion{} @code{bac bbc} ).
@item --enable-disabled-builtins
Allow builtin commands to be invoked via @samp{builtin xxx}
even after @code{xxx} has been disabled using @samp{enable -n xxx}.
See @ref{Bash Builtins}, for details of the @code{builtin} and
@code{enable} builtin commands.
@item --enable-command-timing
Include support for recognizing @code{time} as a reserved word and for
displaying timing statistics for the pipeline following @code{time}. This
allows pipelines as well as shell builtins and functions to be timed.
@item --enable-usg-echo-default
Make the @code{echo} builtin expand backslash-escaped characters by default,
without requiring the @samp{-e} option. This makes the Bash @code{echo}
@ -5280,7 +5322,7 @@ version of Bash that you have.
Once you have determined that a bug actually exists, use the
@code{bashbug} command to submit a bug report.
If you have a fix, you are welcome to mail that as well!
If you have a fix, you are encouraged to mail that as well!
Suggestions and `philosophical' bug reports may be mailed
to @code{bug-bash@@prep.ai.MIT.Edu} or posted to the Usenet
newsgroup @code{gnu.bash.bug}.

17
doc/readline.3
View file

@ -6,9 +6,9 @@
.\" Case Western Reserve University
.\" chet@ins.CWRU.Edu
.\"
.\" Last Change: Mon Jul 8 13:07:48 EDT 1996
.\" Last Change: Wed Feb 5 14:13:22 EST 1997
.\"
.TH READLINE 3 "1996 July 8" GNU
.TH READLINE 3 "1997 Feb 5" GNU
.\"
.\" File Name macro. This used to be `.PN', for Path Name,
.\" but Sun doesn't seem to like that very much.
@ -682,9 +682,18 @@ Add this digit to the argument already accumulating, or start a new
argument. M\-\- starts a negative argument.
.TP
.B universal\-argument
Each time this is executed, the argument count is multiplied by four.
This is another way to specify an argument.
If this command is followed by one or more digits, optionally with a
leading minus sign, those digits define the argument.
If the command is followed by digits, executing
.B universal\-argument
again ends the numeric argument, but is otherwise ignored.
As a special case, if this command is immediately followed by a
character that is neither a digit or minus sign, the argument count
for the next command is multiplied by four.
The argument count is initially one, so executing this function the
first time makes the argument count four.
first time makes the argument count four, a second time makes the
argument count sixteen, and so on.
.PD
.SS Completing
.PP