bash-hackers-wiki/docs/internals/shell_options.md

# 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](/commands/builtin/shopt).

## 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](/syntax/shellvars#LINES) and
[COLUMNS](/syntax/shellvars#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](/syntax/expansion/globs).

### 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](/syntax/pattern) features are
enabled. See the important note below under [Parser
configurations](#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](/syntax/pe) enclosed in double quotes. See the
important note below under [Parser
configurations](#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](/syntax/shellvars#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](/syntax/shellvars#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](/scripting/basics#comments) 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](#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

-   Internal: [shopt builtin command](/commands/builtin/shopt)
-   Internal: [set builtin command](/commands/builtin/set)