Path: utzoo!mnetor!tmsoft!torsqnt!hybrid!scifi!bywater!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.questions
Subject: Re: Simple Question
Keywords: group  newgrp
Message-ID: <5856@auspex.auspex.com>
Date: 11 Feb 91 01:31:54 GMT
References: <1991Feb9.215744.6663@iitmax.iit.edu> <15153@smoke.brl.mil>
Organization: Auspex Systems, Santa Clara
Lines: 14

>There are also various hybrid systems that implement both methods.

I presume Doug is referring here to the fact that some systems let a
process be in more than one group (the limit in many systems is larger
than 8; it's 16 in 4.3BSD and many other systems, and may be
(configurably?) higher than 16 in S5R4), but don't always assign a
newly-created file the group ID of the parent directory.  The model used
in SunOS 4.x (unless a file system is mounted with the "always use the
parent directory") flag, and in S5R4, is that if the parent directory
doesn't have the set-GID bit set, the GID is the effective group ID, and
if it has that bit set, it's the GID of the parent directory.

(Those systems may also have a "newgrp" command to let you set the
effective group ID.)