The Open Group Base Specifications Issue 8

> while true $(($x > 5 && $y <= 25))

That's good that it wasn't adopted. I think one of the primary points of usefulness of these commands is as substitutes for whatever other commands the admin may like. Like if you want a user to not have a login shell, you can set the shell to /bin/false. fakechroot also uses /bin/true to substitute other commands like systemctl and ischroot.[1] It just works best if true always returns true regardless of arguments, ditto false.

The example use case isn't compelling either. In bash, you'd do this:

  while (( $x > 5 && $y <= 25 ))

[1] https://github.com/dex4er/fakechroot/blob/master/scripts/deb...