colemar/var.md

Last active December 16, 2025 18:06

Star (0) You must be signed in to star a gist
Fork (0) You must be signed in to fork a gist

Select an option

Learn more about clone URLs
Clone this repository at <script src="https://gist.github.com/colemar/cef6c8c2b13b1da50338d1ce934ee591.js"></script>
Save colemar/cef6c8c2b13b1da50338d1ce934ee591 to your computer and use it in GitHub Desktop.

Download ZIP

Bash Variable States Matrix

Raw

var.md

Bash Variable States Matrix

Command	`declare -p var`	`[[ -v var ]]`	`set +u; [[ $var ]]` `set -u; [[ ${var:-} ]]`	`set -u; [[ $var ]]`
`unset var`	FALSE ($?==1)	FALSE	FALSE	CRASH (unbound)
`declare var`	`var`	FALSE	FALSE	CRASH (unbound)
`declare var=`	`var=""`	TRUE	FALSE	FALSE
`declare var=1`	`var="1"`	TRUE	TRUE	TRUE

Author

colemar commented Dec 16, 2025

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment