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From: net@tub.UUCP (Oliver Laumann)
Newsgroups: comp.unix.questions
Subject: Re: killing processes
Message-ID: <856@tub.UUCP>
Date: 4 Jun 89 11:52:49 GMT
References: <8373@june.cs.washington.edu> <3440@orca.WV.TEK.COM> <190@sopwith.UUCP> <869@mtxinu.UUCP> <10356@smoke.BRL.MIL>
Reply-To: net@tub.UUCP (Oliver Laumann)
Organization: Technical University of Berlin, Germany
Lines: 21

In article <10356@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
> In article <869@mtxinu.UUCP> shore@mtxinu.UUCP (Melinda Shore) writes:
> >... xterm is usually setuid root so that it can write on utmp.
> 
> The following is more a comment for wizards, but:
> It really is a shame that a 350Kb program has to be given unlimited access
> rights just so it can perform such a simple task.

This is not the real reason.  The real reason is that "xterm" must
call chown() on a newly allocate pseudo-tty.  As you certainly know,
under 4.x BSD and "related" systems such as SunOS, only the super-user
may change the owner of a file.

The "shame" actually is that there is no easy and standardized way for
applications like xterm, screen, Suntools, etc. to allocate a pseudo-tty
with the correct owner and to create and remove a corresponding entry in
/etc/utmp.  This should probably be handled by a server process (to make
sure that entries in /etc/utmp are removed on exit).

--
Oliver Laumann              net@TUB.BITNET              net@tub.UUCP