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bash-hackers-wiki/docs/internals/shell_options.md
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List of shell options

![](keywords>bash shell scripting options runtime variable behaviour)

This information was taken from a Bash version "4.1", every now and then new options are added, so likely, this list isn't complete.

The shell-options can be set with the shopt builtin command.

Shell options

autocd

Option: autocd Since: 4.0-alpha

Shell mode: interactive only Default: off

If set, a command name that is the name of a directory is executed as if it were the argument to the cd command.

assoc_expand_once

Option: assoc_expand_once Since: 5.0-alpha

Shell mode: all Default: off

If set, Bash attempts to expand associative array options only once.

cdable_vars

Option: cdable_vars Since: unknown

Shell mode: all Default: off

Treat every non-directory argument to the cd-command as variable name containing a directory to cd into.

cdspell

Option: cdspell Since: unknown

Shell mode: interactive only Default: off

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 one character too many. If a correction is found, the corrected file name is printed, and the command proceeds.

checkhash

Option: checkhash Since: unknown

Shell mode: all Default: off

If 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.

checkjobs

Option: checkjobs Since: 4.0-alpha

Shell mode: interactive only Default: off

If set, Bash lists the status of any stopped and running jobs before exiting an interactive shell. If any jobs are running, this causes the exit to be deferred until a second exit is attempted without an intervening command. The shell always postpones exiting if any jobs are stopped.

checkwinsize

Option: checkwinsize Since: unknown

Shell mode: all Default: on

If set, Bash checks the window size after each command and, if necessary, updates the values of the variables LINES and COLUMNS.

cmdhist

Option: cmdhist Since: unknown

Shell mode: all Default: off

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.

compat31

Option: compat31 Since: 3.2

Shell mode: all Default: off

Compatiblity mode for Bash 3.1

compat32

Option: compat32 Since: 4.0

Shell mode: all Default: off

Compatiblity mode for Bash 3.2

compat40

Option: compat40 Since: 4.1-beta

Shell mode: all Default: off

Compatiblity mode for Bash 4.0

compat41

Option: compat41 Since: 4.2-alpha

Shell mode: all Default: off

Compatiblity mode for Bash 4.1

compat42

Option: compat42 Since: 4.3-alpha

Shell mode: all Default: off

Compatiblity mode for Bash 4.2

compat43

Option: compat43 Since: 4.4-alpha

Shell mode: all Default: off

Compatiblity mode for Bash 4.3

compat44

Option: compat44 Since: 5.0-alpha

Shell mode: all Default: off

Compatiblity mode for Bash 4.4

direxpand

Option: direxpand Since: 4.3-alpha

Shell mode: all Default: off (unless changed on compile-time with --enable-direxpand-default)

If set, bash replaces directory names with the results of word expansion when performing filename completion. This changes the contents of the readline editing buffer. If not set, bash attempts to preserve what the user typed.

dirspell

Option: dirspell Since: 4.0-alpha

Shell mode: all Default: off

If set, Bash will perform spelling corrections on directory names to match a glob.

dotglob

Option: dotglob Since: unknown

Shell mode: all Default: off

If set, Bash includes filenames beginning with a . (dot) in the results of pathname expansion.

execfail

Option: execfail Since: unknown

Shell mode: non-interactive Default: off

If 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

Option: expand_aliases Since: unknown

Shell mode: all Default: on (interactive), off (non-interactive)

If set, aliases are expanded. This option is enabled by default for interactive shells.

extdebug

Option: extdebug Since: 3.0-alpha

Shell mode: all Default: off

If set, behavior intended for use by debuggers is enabled.

extglob

Option: extglob Since: 2.02-alpha1

Shell mode: all Default: off

If set, the extended pattern matching features are enabled. See the important note below under Parser configurations.

extquote

Option: extquote Since: 3.0-alpha (?)

Shell mode: all Default: on

If set, $'string' and $"string" quoting is performed within parameter expansions enclosed in double quotes. See the important note below under Parser configurations.

failglob

Option: failglob Since: 3.0-alpha

Shell mode: all Default: off

If set, patterns which fail to match filenames during pathname expansion result in an error message.

force_fignore

Option: force_fignore Since: 3.0-alpha

Shell mode: interactive Default: on

If set, the suffixes specified by the FIGNORE shell variable cause words to be ignored when performing word completion even if the ignored words are the only possible completions. This option is enabled by default.

globasciiranges

Option: globasciiranges Since: 4.3-alpha

Shell mode: all Default: on (configurable at compile time)

If set, range expressions used in pattern matching behave as if in the traditional C locale when performing comparisons. That is, the current locale's collating sequence is not taken into account, so b will not collate between A and B, and upper-case and lower-case ASCII characters will collate together.

globstar

Option: globstar Since: 4.0-alpha

Shell mode: all Default: off

If set, recursive globbing with ** is enabled.

gnu_errfmt

Option: gnu_errfmt Since: 3.0-alpha

Shell mode: all Default: off

If set, shell error messages are written in the "standard GNU error message format".

histappend

Option: histappend Since: unknown

Shell mode: interactive (?) Default: off

If set, the history list is appended to the file named by the value of the HISTFILE variable when the shell exits, rather than overwriting the file.

histreedit

Option: histreedit Since: unknown

Shell mode: interactive (?) Default: off

If set, and readline is being used, a user is given the opportunity to re-edit a failed history substitution.

histverify

Option: histverify Since: unknown

Shell mode: interactive (?) Default: off

Allow to review a history substitution result by loading the resulting line into the editing buffer, rather than directly executing it.

hostcomplete

Option: hostcomplete Since: 2.0-alpha3

Shell mode: interactive (?) Default: on

If set, Bash completion also completes hostnames. On by default.

huponexit

Option: huponexit Since: 2.02-alpha1

Shell mode: interactive login Default: off

If set, Bash will send the SIGHUP signal to all jobs when an interactive login shell exits.

interactive_comments

Option: interactive_comments Since: unknown

Shell mode: interactive Default: on

Allow commenting in interactive shells, on by default.

lastpipe

Option: lastpipe Since: 4.2-alpha

Shell mode: all Default: off

If set, and job control is not active, the shell runs the last command of a pipeline not executed in the background in the current shell environment.

lithist

Option: lithist Since: unknown

Shell mode: interactive Default: off

If set, and the #cmdhist option is enabled, multi-line commands are saved to the history with embedded newlines rather than using semicolon separators where possible.

localvar_inherit

Option: localvar_inherit Since: 5.0-alpha

Shell mode: all Default: off

If this option is set, a local variable inherits the value of a variable with the same name at the nearest preceding scope.

login_shell

Option: login_shell Since: 2.05a-alpha1

Shell mode: all Default: n/a

The option is set when Bash is a login shell. This is a readonly option.

mailwarn

Option: mailwarn Since: unknown

Shell mode: interactive (?) Default: off

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

Option: mailwarn Since: unknown

Shell mode: interactive (?) Default: off

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

Option: nocaseglob Since: 2.02-alpha1

Shell mode: all Default: off

If set, Bash matches filenames in a case-insensitive fashion when performing pathname expansion.

nocasematch

Option: nocasematch Since: 3.1-alpha1

Shell mode: all Default: off

If set, Bash matches patterns in a case-insensitive fashion when performing matching while executing case or [[ conditional commands.

nullglob

Option: nullglob Since: unknown

Shell mode: all Default: off

If set, Bash allows patterns which match no files to expand to a null string, rather than themselves.

progcomp

Option: progcomp Since: 2.04-alpha1

Shell mode: interactive (?) Default: on

If set, the programmable completion facilities are enabled. This option is enabled by default.

promptvars

Option: promptvars Since: unknown

Shell mode: interactive Default: on

If set, prompt strings undergo parameter expansion, command substitution, arithmetic expansion, and quote removal after being expanded using the prompt special sequences. This option is enabled by default.

restricted_shell

Option: restricted_shell Since: 2.03-alpha

Shell mode: interactive (?) Default: off

The option is set when Bash is a restricted shell. This is a readonly option.

shift_verbose

Option: shift_verbose Since: unknown

Shell mode: all Default: off, on in POSIX mode

If set, the shift builtin prints an error message when the shift count exceeds the number of positional parameters.

sourcepath

Option: sourcepath Since: unknown

Shell mode: all Default: on

If set, the source builtin command uses the value of PATH to find the directory containing the file supplied as an argument. This option is enabled by default.

syslog_history

Option: syslog_history Since: 5.0-alpha

Shell mode: unknown Default: off

If set, the shell history is sent to syslog.

This option is undocumented and available only if the shell supports syslog.

xpg_echo

Option: xpg_echo Since: 2.04-beta1

Shell mode: all Default: off

If set, the echo-builtin command expands backslash-escape sequences by default (POSIX, SUS, XPG).

Parser configurations

Parser configurations change the way the Bash parser recognizes the syntax when parsing a line. This, of course, is impossible for a line that already was parsed.

There are two options that influence the parsing this way:

  • extglob
  • extquote

Consequence: You can't use the new syntax (e.g. the extended globbing syntax) and the command to enable it in the same line.

$ shopt -s extglob; echo !(*.txt) # this is the WRONG way!
-bash: syntax error near unexpected token `('

You have to configure the parser before a line with new syntax is parsed:

$ shopt -s extglob # standalone - CORRECT way!
$ echo !(*.txt)
...

See also