colemar

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