if
if
TLDR
Echo a different thing depending on a command's success
$ [command] && echo "success" || echo "failure"
Full if syntax
$ if [condition]; then echo "true"; else echo "false"; fi
List available if conditions
$ help test
Test if a given variable is empty
$ if [[ -z $GIT_BRANCH ]]; then echo "true"; else echo "false"; fi
Test if a file exists
$ if [[ -e [filename] ]]; then echo "true"; else echo "false"; fi
If directory not exists
$ if [[ ! -d [path/to/directory] ]]; then echo "true"; else echo "false"; fi