Shell Options
Syntax
shopt [-pqsu] [-o] [optname ...]
Options
-s Enable (set) each optname
-u Disable (unset) each optname.
-p Display a list of all settable options, with an indication of
whether or not each is set. The output is displayed in a form
that can be reused as input. (-p is the default action)
-q Suppresses normal output; the return status indicates whether the optname
is set or unset. If multiple optname arguments are given with '-q',
the return status is zero if all optnames are enabled; non-zero otherwise.
-o Restricts the values of optname to be those defined for the '-o' option to
the set builtin.
If either '-s' or '-u' is used with no optname arguments, the display is limited to those options which are set or unset, respectively.
Unless otherwise noted, the shopt options are disabled (off) by default.
The return status is zero unless an optname was *not* enabled or was not a valid shell option.
optnames:
cdable_vars
If this is set, an argument to the cd builtin command that
is not a directory is assumed to be the name of a variable whose value is
the directory to change to.
cdspell
If set, minor errors in the spelling of a directory component in a cd
command will be corrected. 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 only used
by interactive shells.
checkhash
If this is set, Bash checks that a command found in the hash table exists
before trying to execute it. If a hashed command no longer exists, a normal
path search is performed.
checkwinsize
If set, Bash checks the window size after each command and, if necessary,
updates the values of LINES and COLUMNS.
cmdhist
If set, Bash attempts to save all lines of a multiple-line command in the
same history entry. This allows easy re-editing of multi-line commands.
dotglob
If set, Bash includes filenames beginning with a '.' in the results of filename
expansion.
execfail
If this is set, a non-interactive shell will not exit if it cannot execute
the file specified as an argument to the exec builtin command.
An interactive shell does not exit if exec fails.
expand_aliases
If set, aliases are expanded.
This option is enabled by default for interactive shells.
extglob
If set, the extended pattern matching features described above are enabled.
histappend
If set, the history list is appended to the history file when the shell exits,
rather than overwriting the history file.
shopt -s histappend
To append every line to history individually set:
PROMPT_COMMAND='history -a'
With these two settings, a new shell will get the history lines from all previous
shells instead of the default 'last window closed'>history
(the history file is named by the value of the HISTFILE variable)
histreedit
If set, and Readline is being used, a user is given the opportunity to re-edit
a failed history substitution.
histverify
If set, and Readline is being used, the results of history substitution
are not immediately passed to the shell parser. Instead, the resulting line
is loaded into the Readline editing buffer, allowing further modification.
hostcomplete
If set, and Readline is being used, Bash will attempt to perform hostname
completion when a word containing a '@' is being completed.
This option is enabled by default.
huponexit
If set, Bash will send SIGHUP to all jobs when an interactive login shell exits.
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.
This option is enabled by default.
lithist
If enabled, and the cmdhist option is enabled, multi-line commands
are saved to the history with embedded newlines rather than using semicolon
separators where possible.
mailwarn
If set, and a file that Bash is checking for mail has been accessed since the
last time it was checked, the message "The mail in mailfile has been read" is
displayed.
no_empty_cmd_completion
If set, and Readline is being used, Bash will not attempt to search the
PATH for possible completions when completion is attempted on
an empty line.
nocaseglob
If set, Bash matches filenames in a case-insensitive fashion when performing
filename expansion.
nullglob
If set, Bash allows filename patterns which match no files to expand to
a null string, rather than themselves.
progcomp
If set, the programmable completion facilities are enabled.
This option is enabled by default.
promptvars
If set, prompt strings undergo variable and parameter expansion after being
expanded. This option is enabled by default.
restricted_shell
The shell sets this option if it is started in restricted mode. The value
can not be changed. This is not reset when the startup files are executed,
allowing the startup files to discover whether or not a shell is restricted.
shift_verbose
If this is set, the shift builtin prints an error message when
the shift count exceeds the number of positional parameters.
sourcepath
If set, the source builtin uses the value of PATH to find the directory containing
the file supplied as an argument. This option is enabled by default.
xpg_echo
If set, the echo builtin expands backslash-escape sequences
by default.
'shopt' is a BASH builtin command.
Turn on spell checker for directory names in the cd builtin:
$ shopt -s cdspell
“The dogma of the ghost in the machine” ~ Gilbert Ryle
env - Display, set, or remove environment variables.
function - Define Function Macros.
local - Create variables.
logname - Print current login name.
set - Manipulate shell variables and functions.
uname - Print system information.
users - Print login names of users currently logged in.
who - Print who is currently logged in.
Equivalent Windows commands: SETLOCAL - Set options to control the visibility of variables.