string-empty-or-unset
Published at 2024-01-16
Last update over 365 days ago
Licensed under CC BY-NC-SA 4.0
softwares-and-tools
fish
string
https://stackoverflow.com/questions/47743015/fish-shell-how-to-check-if-a-variable-is-set-empty
unset 就是 empty. 但是 string length empty 不会输出,string length "" 输出 0
test -n "$var": var set and its length >= 1
test -z "$var": var set and its length == 0
但是 test -z 可以不接收参数,test -n 不接收居然会返回 true.