|Abbreviation|Name|Effect|

-B

brace expansion

Enable brace expansion (default setting = on)

+B

brace expansion

Disable brace expansion

-C

noclobber

Prevent overwriting of files by redirection (may be overridden by >|)

-D

(none)

List double-quoted strings prefixed by $, but do not execute commands in script

-a

allexport

Export all defined variables

-b

notify

Notify when jobs running in background terminate (not of much use in a script)

-c …

(none)

Read commands from

checkjobs

 

Informs user of any open jobs upon shell exit. Introduced in version 4 of Bash, and still “experimental.” Usage: shopt -s checkjobs (Caution: may hang!)

-e

errexit

Abort script at first error, when a command exits with non-zero status (except in until or while loops, if-tests, list constructs)

-f

noglob

Filename expansion (globbing) disabled

globstar

globbing star-match

Enables the ** globbing operator (version 4+ of Bash). Usage: shopt -s globstar

-i

interactive

Script runs in interactive mode

-n

noexec

Read commands in script, but do not execute them (syntax check)

-o Option-Name

(none)

Invoke the Option-Name option

-o posix

POSIX

Change the behavior of Bash, or invoked script, to conform to POSIX standard.

-o pipefail

pipe failure

Causes a pipeline to return the exit status of the last command in the pipe that returned a non-zero return value.

-p

privileged

Script runs as “suid” (caution!)

-r

restricted

Script runs in restricted mode (see Chapter 22).

-s

stdin

Read commands from stdin

-t

(none)

Exit after first command

-u

nounset

Attempt to use undefined variable outputs error message, and forces an exit

-v

verbose

Print each command to stdout before executing it

-x

xtrace

Similar to -v, but expands commands

(none)

End of options flag. All other arguments are positional parameters.

(none)

Unset positional parameters. If arguments given (— arg1 arg2), positional parameters set to arguments.