Why take a perfectly readable if-statement and turn it into something, 99.9% of people would need to lookup. Concise != better. You can make it one line with:

    [ -z "$1" ] && { echo "missing argument, aborting." 1>&2; exit 1 }

the people writing it are doing it for themselves probably. i wouldn’t expect it to survive a code review. the necessity of using esoteric bash features or syntax is a pretty good smell that you should be using something else imo.

different strokes of course.

This question seems to pop up all over the place, so I took some time to answer it here:

https://refp.se/articles/your-shell-and-the-magic-colon#why-...

I believe you missed a semicolon after `exit 1` and before `}`. `}` closes the opening `{` only at the start of a command (POSIX rules; don't remember now if bash recognizes it when it's just a command argument).

I'm just too used to how parsing works in Zsh. For bash and sh, there is indeed should be a semicolon.

In this specific case, echo can't fail to there's no need for any of that:

  [ -z "$1" ] && echo "fail" >&2 && exit 1

Echo will fail here when stderr is closed. For example when the caller of the script pipes stderr to another command and that command exits.