7.1.1. Shell options

The shell has several options that can be set or unset. Some are descripted here. You can get an overview with set -o and more explanation with help set.

Options are set with set -o <option> and switch off with set +o option. For most options there is also a one-letter way to set/unset the option.

set -f/+f

set -o/+o noglob

switch on/off the globbing of filenames (4.1.2)

set -B/+B

set -o/+o braceexpand

switch on/off the brace expansion of filenames (4.1.2)

set -a/+a

set -o/+o exportall

if switched on, all variables that are set or changed are automatically exported (see 7.1.3)

set -o vi

set -o emacs

select the style of accessing the history (see 7.1.2)

The following options are more usefull is programming in the shell (see 7.3)

set -e

exit the shell on first error

set -u

exit the shell when unset variables are used

set -v

print every line before it is executed

set -x

print each command and its arguments before it is executed