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From: guy@sun.uucp (Guy Harris)
Newsgroups: net.bugs.uucp
Subject: Re: Read permission on /etc/phones, really kill(pid,0) ?
Message-ID: <2402@sun.uucp>
Date: Tue, 9-Jul-85 19:16:36 EDT
Article-I.D.: sun.2402
Posted: Tue Jul  9 19:16:36 1985
Date-Received: Fri, 12-Jul-85 03:29:32 EDT
References: <472@qantel.UUCP> <170@motel6.UUCP> <154@telesoft.UUCP> <525@down.FUN> <140@ukc.UUCP>
Organization: Sun Microsystems, Inc.
Lines: 15

> On which versions of Unix will kill(pid,0) return a status indicating wether
> the process (pid) is still running?
> 
> It doesn't on the V7 and BSD 4.1 locally.  It appears to on BSD 4.2.
> What about USG unixes, Xenix and XELOS?

"kill" with signal 0 also returns a status on System V; I believe it did so
in System III also.  As such, it also works on XELOS (which is a System V
Release 2 port) and probably does so on Xenix 3.0 (which is based on System
III).  The same argument can be applied to any other UNIX-based system out
there based on 4.2BSD, System III, or System V; there's no need to ask
separately about those systems - asking about the version they're based on
is sufficient.

	Guy Harris