[microtherion]

I seem to recall that perl used to shell out to /bin/sh for some related task...

[microtherion]

Yep, still there in the latest perl5: Perl_start_glob https://github.com/Perl/perl5/blob/blead/doio.c

It's somewhat messier than I remember, because it uses csh as the first choice and falls back to sh.