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<A NAME="PAGENUM-40"><P>Page 40</P></A>
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</TD><TD>
If the popd command is successful, a dirs is performed as well, and the return
status is 0. popd returns False if an illegal option is encountered, the directory stack
is empty, a nonexistent directory stack entry is specified, or the directory change fails.
</TD></TR><TR><TD>
pushd [dir] pushd +/_n
</TD><TD>
Adds a directory to the top of the directory stack, or rotates the stack, making
the new top of the stack the current working directory. With no arguments,
exchanges the top two directories and returns 0, unless the directory stack is empty.
</TD></TR></TABLE>
<TABLE>
<TR><TD>
+n
</TD><TD>
Rotates the stack so that the nth directory (counting from
the left of the list shown by dirs) is at the top.
</TD></TR><TR><TD>
_n
</TD><TD>
Rotates the stack so that the nth directory (counting from
the right) is at the top.
</TD></TR><TR><TD>
dir
</TD><TD>
Adds dir to the directory stack at the top, making it the
new current working directory.
</TD></TR></TABLE>
<TABLE>
<TR><TD>
</TD><TD>
If the pushd command is successful, a dirs is performed as well.
If the first form is used, pushd returns 0 unless the
cd to dir fails. With the second form, pushd returns
0 unless the directory stack is empty, a nonexistent directory stack element is
specified, or the directory change to the specified new current directory fails.
</TD></TR><TR><TD>
pwd
</TD><TD>
Print the absolute pathname of the current working directory. The path
printed contains no symbolic links if the _P option to the
set builtin command is set. (See also the description of
nolinks under "Shell Variables," earlier in this manual
page.) The return status is 0 unless an error occurs while reading the pathname of
the current directory.
</TD></TR><TR><TD>
read [_r][name ...]
</TD><TD>
One line is read from the standard input, and the first word is assigned to the
first name, the second word to the second name, and so on, with leftover words
assigned to the last name. Only the characters in
IFS are recognized as word delimiters. If no names are supplied, the line read is assigned to the variable
REPLY. The return code is zero, unless end-of-file is encountered. If the
-r option is given, a backslash-newline pair is not ignored, and the backslash is considered to be part of the line.
</TD></TR><TR><TD>
readonly [_f][name ...]
</TD><TD>
The given names are marked
readonly and the values of these names may not be
</TD></TR><TR><TD>
readonly -p
</TD><TD>
changed by subsequent assignment. If the
_f option is supplied, the functions corresponding to the names are so marked. If no arguments are given, or if the <BR>
_p option is supplied, a list of all readonly names is printed. An argument of
— disables option checking for the rest of the arguments. The return status is
0 unless an illegal option is encountered, one of the names is not a legal shell variable
name, or _f is supplied with a name that is not a function.
</TD></TR><TR><TD>
return [n]
</TD><TD>
Causes a function to exit with the return value specified by
n. If n is omitted, the return status is that of the last command executed in the function body. If
used outside a function, but during execution of a script by the
. (source) command, it causes the shell to stop executing that script and return
either n or the exit status of the last command executed within the script as the exit status of the script. If
used outside a function and not during execution of a script by
(. , the return status is False.
</TD></TR><TR><TD>
set [—abefhkmnptuvxldCHP]
</TD><TD>
</TD></TR><TR><TD>
[-o option][arg ...]
</TD></TR></TABLE>
<TABLE>
<TR><TD>
</TD><TD>
_a
</TD><TD>
Automatically mark variables that are modified or created
for export to the environment of subsequent commands.
</TD></TR><TR><TD>
</TD><TD>
_b
</TD><TD>
Cause the status of terminated background jobs to be
reported immediately, rather than before the next primary
prompt. (Also see notify under "Shell Variables.")
</TD></TR><TR><TD>
</TD><TD>
_e
</TD><TD>
Exit immediately if a simple command (see "Shell
Grammar," earlier in this manual page) exits with a non_zero status.
The shell does not exit if the command that fails is part of an
until
</TD></TR></TABLE>
<A NAME="PAGENUM-41"><P>Page 41</P></A>
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</TD><TD>
</TD><TD>
or while loop, part of an if statement, part of a
&& or || list, or if the command's return value is being inverted via!.
</TD></TR><TR><TD>
</TD><TD>
_f
</TD><TD>
Disable pathname expansion.
</TD></TR><TR><TD>
</TD><TD>
_h
</TD><TD>
Locate and remember function commands as functions
are defined. Function commands are normally looked up
when the function is executed.
</TD></TR><TR><TD>
</TD><TD>
_k
</TD><TD>
All keyword arguments are placed in the environment for
a command, not just those that precede the command name.
</TD></TR><TR><TD>
</TD><TD>
_m
</TD><TD>
Monitor mode. Job control is enabled. This flag is on
by default for interactive shells on systems that support it.
(See "Job Control," earlier in this manual page.)
Background processes run in a separate process group and a line
containing their exit status is printed upon their completion.
</TD></TR><TR><TD>
</TD><TD>
_n
</TD><TD>
Read commands but do not execute them. This may be
used to check a shell script for syntax errors. This is ignored
for interactive shells.
</TD></TR><TR><TD>
</TD><TD>
_o option-name
</TD><TD>
The option-name can be one of the following:
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
allexport—Same as _a.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
braceexpand—The shell performs brace expansion. (See
"Brace Expansion," earlier in this manual page.) This is on by default.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
emacs—Use an emacs-style command line editing
interface. This is enabled by default when the shell is interactive,
unless the shell is started with the
_nolineediting option.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
errexit—Same as _e.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
histexpand—Same as _H.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
ignoreeof—The effect is as if the shell
command `IGNOREEOF=10' had been executed. (See "Shell Variables.")
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
interactive_comments—Allow a word beginning
with # to cause that word and all remaining characters on that line to
be ignored in an interactive shell. (See "Comments," earlier
in this manual page.)
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
monitor—Same as _m.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
noclobber—Same as _C.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
noexec—Same as _n.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
noglob—Same as _f.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
nohash—Same as _d.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
notify—Same as _b.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
nounset—Same as _u.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
physical—Same as _P.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
posix—Change the behavior of bash where the
default operation differs from the POSIX 1003.2 standard to
match the standard.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
privileged—Same as _p.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
verbose—Same as _v.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
vi—Use a vi-style command line editing interface.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
xtrace—Same as _x.
</TD></TR><TR><TD>
</TD><TD>
</TD><TD>
If no option-name is supplied, the values of the current
options are printed.
</TD></TR></TABLE>
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