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B.6. set Options
Table B-7 lists the options that can be turned on with the set -arg command. All are initially off except
where noted. Full Names, where listed, are arguments to set that can be used with set -o. The Full
Names braceexpand, histexpand, history, keyword, and onecmd are not available in versions of
bash prior to 2.0. Also, in those versions, hashing is switched with -d.
Table B-7. Options to set
Option
Full name
Meaning
-a
allexport
-B
braceexpand The shell performs brace expansion. This is on by default.
-b
notify
Report the status of terminating background jobs immediately.
-C
noclobber
Don't allow redirection to overwrite existing files.
errtrace
Any trap on ERR is inherited by shell functions, command substitutions, and
commands executed in a subshell environment.
errexit
Exit the shell when a simple command exits with non-zero status. A simple
command is a command not part of a while, until, or if; or part of a && or ||
list; or a command whose return value is inverted by !.
emacs
Use emacs-style command-line editing.
-f
noglob
Disable pathname expansion.
-H
histexpand
Enable ! style history substitution. On by default in an interactive shell.
history
Enable command history. On by default in interactive shells.
hashall
Disable the hashing of commands.
ignoreeof
Disallow CTRL-D to exit the shell.
-k
keyword
Place keyword arguments in the environment for a command.
-m
monitor
Enable job control (on by default in interactive shells).
-E
-e
-h
Export all subsequently defined or modified variables.