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Newsgroups: comp.os.386bsd.bugs Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!howland.reston.ans.net!news.ans.net!cmcl2!prism.poly.edu!kapela From: kapela@poly.edu (Theodore S. Kapela) Subject: Re: bug with ufs file creation Message-ID: <CD1Bux.JqL@poly.edu> Organization: Polytechnic University, New York References: <CCyLF6.n6@kithrup.com> <322@rook.ukc.ac.uk> <CCzu78.DJD@kithrup.com> Date: Wed, 8 Sep 1993 12:25:45 GMT Lines: 39 In article <CCzu78.DJD@kithrup.com> sef@kithrup.com (Sean Eric Fagan) writes: >In article <322@rook.ukc.ac.uk> dac@ukc.ac.uk (David Clear) writes: >>That's true BSD file creation semantics > >"true BSD file creation semantics" are broken. If I cannot do > > chgrp bin foo > >without being in group bin, why is foo going to be in group bin depending >on where I create it? Remember where BSD came from: RESEARCH The intended "audience" (group of users) was a bunch of researchers openly working together. To facilitate this, if a group is working on a project, and all of its files are under some heirarchy with a single root (Say, /usr/develop), then it is much more productive to have *all* files under that heirarchy have the same group ownership, so all those working on that project can readily have access (assuming the umask was set right, which it normally was - the default would always be 022 or 002). There was no need to ask a specific user to explicitly change the ownerships (user/group) of a file to allow others in his group to use it. You can't count on all users working on a project to have the same primary group (IE: group in /etc/passwd), especially since many users would move between projects often, or would work on more than one project at once. >At least the SGID bit is somewhat intuitive (since SGID means, inheiret >the group id, for processes; it is just extended for directories and >files, now). Not exactly. SGID and SUID bits on an executable mean to set the EFFECTIVE Group ID or User ID. There is a difference, though it is a subtle one unless you write sofware that uses/needs to be aware of it. -- Theodore S. Kapela Center for Applied Large-Scale Computing Polytechnic University kapela@poly.edu