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From: mouse@mcgill-vision.UUCP (der Mouse)
Newsgroups: comp.unix.wizards
Subject: Re: Setting process groups
Message-ID: <910@mcgill-vision.UUCP>
Date: Wed, 18-Nov-87 07:21:21 EST
Article-I.D.: mcgill-v.910
Posted: Wed Nov 18 07:21:21 1987
Date-Received: Fri, 27-Nov-87 00:03:43 EST
References: <1765@unc.cs.unc.edu>
Organization: McGill University, Montreal
Lines: 26

In article <1765@unc.cs.unc.edu>, southard@unc.cs.unc.edu (Scott Southard) writes:
> I am writing a program that creates several child processes, and at
> some point I would like to kill all the children, but not the parent,
> with a killpg() call.  How do I set the process group id of all the
> children to the same id, but not to the id used by the parent?

setpgrp(2).  (Please mention what sort of system you are on.  In this
case, I assume, since you are talking about process groups, that you
are on a Berkeley derivative UNIX.)

> Can I just pick a process group id to assign to the children that is
> different than the one used by the parent?  How can I determine what
> process group id's are not in use?  Any help on this would be
> appreciated.

The only way, as far as I know, to determine what process groups are in
use is a ps-like program which scans the process table.

However, the convention is that the process group of all processes in a
job is the process ID of the job leader.  Thus, for your application, I
would say you could pick one of the children and use its process ID as
the process group number to give all of them.

					der Mouse

				(mouse@mcgill-vision.uucp)