From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <3643bbeabcff786c34b15f06876f75d2@plan9.bell-labs.com>
From: jmk@plan9.bell-labs.com
To: 9fans@cse.psu.edu
Subject: Re: [9fans] removing users
In-Reply-To: <20030619182445.GA6452@thefrayedknot.armory.com>
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Date: Thu, 19 Jun 2003 14:48:59 -0400
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On Thu Jun 19 14:25:21 EDT 2003, afrayedknot@thefrayedknot.armory.com wrote:
> so i should rename them all to some null user which is unable to log in?
>
> On Thu, Jun 19, 2003 at 01:50:53PM -0400, Russ Cox wrote:
> > If you're running dumps, it's not a good idea to remove
> > users -- their ids will still be found looking in the dump.
> >
> > You can rename the uname with 'uname old %new' but
> > you shouldn't get rid of the uid.
> >
> > Russ

the format of users file is:

	id:name:[leader]:[members[,members]]

	id is what is used to store in the file system
	name is what the outside world (9p) sees and deals with
	leader is the group leader (may be nil)
	members is a comma-separated list of who is in the group

a check is made when the users file is read by the server that
there is only one id<->name mapping.

so, say we have
	bob:bob::
and create some files. these files are on permanent storage in the
back end (venti, the original standalone fs, whatever) and the id 'bob'
is tied to those files irrevocably.

if bob leaves, we just need to turn off his ability to authenticate
to the server, there's no real need to remove his files and, in fact, those
files of his in the dump cannot be changed or removed.

the idea is that if a new bob arrives we can still give him the name bob
by changing the old bob entry to
	bob:bobwholeft::
(this is accomplished by using the 'uname' command in fossilcons(8), e.g.
	uname bob %bobwholeft
)
and then making a new entry
	newbob:bob::
via
	uname bob newbob

but there no way the new bob can access the old bob's files as they
are stored under different ids.