`set -u` (nounset) vs checking whether I have arguments

bash

Solution

`$#` contains the number of arguments, so you can test for `$1`, `$2`, etc. to exist before accessing them.

if (( $# == 0 )); then
    # no arguments
else
    # have arguments
fi;

Problem

I'm trying to improve this nasty old script. I found an undefined variable error to fix, so I added `set -u` to catch any similar errors. I get an undefined variable error for "$1", because of this code ``` if [ -z "$1" ]; then process "$command" ``` It just wants to know if there are arguments or not. (The behaviour when passed an empty string as the first argument is not intended. It won't be a problem if we happen to fix that as well). What's a good way to check whether we have arguments, when running with `set -u`? The code above won't work if we replace "$1" with "$@", because of the special way "$@" is expanded when there is more than one argument.

Original source