Sorry, yes -- which is why I think the exec hack first show up in the BSD kernel. It was an efficiency trick on the PDP-11's. The idea was to catch the change of shell as soon as possible.

On Fri, Apr 21, 2017 at 10:48 AM, Ron Natalie <ron@ronnatalie.com> wrote:

Oldest actual use in a post I can find is 1997

I did find something I had completely forgot about. The csh used to (probably still does?) differentiate between Bourne shell scripts and csh scripts by looking for #.