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
cdbuiltin 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
cdcommand 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
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
execbuiltin command. An interactive shell does not exit if
execfails. 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
HISTFILEvariable) 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
SIGHUPto 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
cmdhistoption 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
PATHfor 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
shiftbuiltin prints an error message when the shift count exceeds the number of positional parameters. sourcepath If set, the
sourcebuiltin uses the value of
PATHto find the directory containing the file supplied as an argument. This option is enabled by default. xpg_echo If set, the
echobuiltin 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
Related linux commands:
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.