.\" 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.
.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.
.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
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
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 .
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
.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.
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
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
.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
\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
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
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
.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
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
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
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
projects / thirdparty / bash.git / blobdiff