Shopt

External

• https://bash.cyberciti.biz/bash-reference-manual/Bash-Builtins.html#shopt

Internal

• Bash

Overview

Toggle the values of variables controlling optional shell behavior, or lit all settable options, with an indication of whether or not each is set (-s means set, -u means unset).

Options

nullglob

If set, bash allows filename patterns which match no files to expand to a null string, rather than themselves.

shopt -s nullglob

expand_aliases

bash Concepts | Aliases