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From: mike@whuxl.UUCP (BALDWIN)
Newsgroups: net.unix-wizards
Subject: Re: setuid help
Message-ID: <799@whuxl.UUCP>
Date: Mon, 11-Nov-85 19:17:01 EST
Article-I.D.: whuxl.799
Posted: Mon Nov 11 19:17:01 1985
Date-Received: Tue, 12-Nov-85 06:19:34 EST
References: <321@ihnet.UUCP>
Distribution: net
Organization: AT&T Bell Laboratories, Whippany
Lines: 16

> About setuid in UNIX Sys V: any process that execs a setuid program file
> can switch at will between the processes' real uid and the setuid of
> the file. Thus, it can bounce between these two uid's as often as
> necessary. This is an essentially undocumented feature os UNIX Sys V
> (and derivatives, I hope).

Undocumented?  Please folks, read the manual:

SETUID(2)

	If the effective user ID of the calling process is not super-user,
	but the saved set-user (group) ID from exec(2) is equal to uid
	(gid), the effective user (group) ID is set to uid (gid).
-- 
						Michael Baldwin
						{at&t}!whuxl!mike