Path: utzoo!utgpu!water!watmath!clyde!rutgers!sri-unix!ctnews!pyramid!hplabs!hpcea!hpda!hpcupt1!davel
From: davel@hpcupt1.HP.COM (Dave Lennert)
Newsgroups: comp.unix.questions
Subject: Re: wait3 emulation in SYSTEMV ??
Message-ID: <6060006@hpcupt1.HP.COM>
Date: 4 Feb 88 15:07:30 GMT
References: <360@rruxa.UUCP>
Organization: Hewlett Packard, Cupertino
Lines: 19

> However, looking some more into the code, one finds that the
> process group of a zombi process is set to 0 (surprise?!).
> Which leads me to the conclusion that if a processes indead
> calls setprgp() you can test its state by
> 
> 	kill (-childpid, 0)
> 
> provided that the process did not create some children
> which did not call setpgrp().

You assume that the zombie process of interest was formerly a
process group leader (process group ID == process ID).  This
is not necessarily the case.  You are probably thinking that,
csh's that support BSD-style job control, the first command in
a pipeline is always made a process group leader.  This is not
true on shells that do not do this style of job control, and
thus is not true on System V (at least not yet).

-Dave Lennert   HP   ihnp4!hplabs!hpda!davel