Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!hao!ames!pasteur!ucbvax!hplabs!hpda!hpcupt1!davel
From: davel@hpcupt1.HP.COM (Dave Lennert)
Newsgroups: comp.unix.questions
Subject: Re: setting the control terminal (how?)
Message-ID: <6060004@hpcupt1.HP.COM>
Date: 15 Jan 88 04:46:45 GMT
References: <435@picuxa.UUCP>
Organization: Hewlett Packard, Cupertino
Lines: 14

> A setpgrp() will fail to work in a process which has already done a setgprp().

True, but the posted code does a fork() first, which is the only reliable
way to do it, so that it is guaranteed to not already be a process group 
leader.

Short of a kernel bug (as some have suggested), the open() will also
fail to assign a new controlling terminal if the opened terminal is
already a controlling terminal for another process group.

This is all assuming System V (which it appears you are using since your
setpgrp() contains no arguments).  BSD does this slightly magic differently.

-Dave Lennert   HP   ihnp4!hplabs!hpda!davel   uunet!hpda!davel