HP-UX systems have it. Linux can emulate the system call by an appropriately
programmed library call (through judicious use of setreuid()).
--
Sincerely, srb@cuci.nl
Stephen R. van den Berg (AKA BuGless).
"I hate spinach, and I'm glad that I hate it, because if I wouldn't hate it,
I would have to eat it, and I hate it!"