The shopt options are set with shopt -s
arg
and
unset with shopt -u
arg
(see shopt options).
Versions of bash prior to 2.0 had environment
variables to perform some of these settings. Setting them equated to
shopt -s
. The variables (and
corresponding shopt options) were: allow_null_glob_expansion (nullglob), cdable_vars
(cdable_vars), command_oriented_history (cmdhist), glob_dot_filenames
(dotglob), no_exit_ on_failed_exec (execfail)
. These variables
no longer exist.
The options extdebug, failglob,
force_fignore
, and gnu_errfmt
are not available in versions of bash prior to
3.0.
Table A-7. shopt options
Option | Meaning if set |
---|---|
| An argument to cd that is not a directory is assumed to be the name of a variable whose value is the directory to change to. |
| Minor errors in the spelling of a directory supplied to the cd command will be corrected if there is a suitable match. This correction includes missing letters, incorrect letters, and letter transposition. It works for interactive shells only. |
| Commands found in the hash table are checked for
existence before being executed and nonexistence forces a |
| Checks the window size after each command and, if it
has changed, updates the variables |
| Attempt to save all lines of a multiline command in a single history entry. |
| Filenames beginning with a . are included in pathname expansion. |
| A noninteractive shell will not exit if it cannot execute the argument to an exec. Interactive shells do not exit if exec fails. |
| Aliases are expanded. |
| Behavior intended for use by debuggers is enabled.
This includes: the |
| Extended pattern matching features are enabled. |
| Patterns that fail to match filenames during pathname expansion result in an expansion error. |
| The suffixes specified by the |
| Shell error messages are written in the standard GNU error message format. |
| The history list is appended to the file named by the
value of the variable |
| If readline is being used, the opportunity is given for re-editing a failed history substitution. |
| If 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. |
| If readline is being used, an attempt will be made to perform hostname completion when a word beginning with @ is being completed. |
| bash will send |
| Allows a word beginning with # and all subsequent characters on the line to be ignored in an interactive shell. |
| If the |
| If bash is started as a login shell. This is a read-only value. |
| If the file being checked for mail has been accessed since the last time it was checked, the message “The mail in mailfile has been read” is displayed. |
| If readline is being used, no
attempt will be made to search the |
| bash matches filenames in a case-insensitive fashion when performing pathname expansion. |
| Cause patterns that match no files to expand to null strings rather than to themselves. |
| Programmable completion facilities are enabled. Default is on. |
| Prompt strings undergo variable and parameter expansion after being expanded. |
| Set if the shell is started in restricted mode. The value cannot be changed. |
| The shift built-in prints an error if it has shifted past the last positional parameter. |
| The source built-in uses the
value of |
| echo expands backslash-escape sequences by default. |
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