Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!rpi!crdgw1!underdog!volpe
From: volpe@underdog.crd.ge.com (Christopher R Volpe)
Newsgroups: comp.unix.questions
Subject: Re: loginid vs. uid.
Message-ID: <9900@crdgw1.crd.ge.com>
Date: 18 Jul 90 12:04:24 GMT
References: <11399@hydra.gatech.EDU> <232@twg.wimsey.bc.ca>
Sender: news@crdgw1.crd.ge.com
Reply-To: volpe@underdog.crd.ge.com (Christopher R Volpe)
Lines: 13

What exactly does su have to do (when given the "-" option) to *completely*
change your identity so that applications like mail think you are the
person you su'd to rather than the person you su'd from? I once experimented 
with a program (setuid to root) that set real and effective group and
user ids to root, and then execed a c shell. "who" reported the name
I logged in under (which makes sense because of the utmp file), but
applications like mail still thought I was the person I logged in under.
Does mail use the utmp file as well? I tried changing enironment
variables such as HOME and LOGNAME, but they had no effect. 

Chris Volpe
GE Corporate R&D
volpecr@crd.ge.com