Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!cs.utexas.edu!uunet!convex!tchrist@convex.COM
From: tchrist@convex.COM (Tom Christiansen)
Newsgroups: alt.sources.d
Subject: Re: Cmail - check to see who's read their mail - UNIX
Message-ID: <2337@convex.UUCP>
Date: 24 Oct 89 13:45:49 GMT
References: <4006@helios.ee.lbl.gov>
Sender: usenet@convex.UUCP
Reply-To: tchrist@convex.COM (Tom Christiansen)
Organization: CONVEX Software Development, Richardson, TX
Lines: 24

In article <4006@helios.ee.lbl.gov>,
leres@helios.ee.lbl.gov (Craig Leres) writes:

>Note that if a user is logged in and uses biff (or sysline), you can't
>really tell when mail was last read since biff reads new messages as
>they arrive. This is particuarly a problem if the person stays logged
>into a workstation 24 hours a day...

Only if your vendor hasn't fixed biff(1) to save the st_atime from when
it stats the file and restore it with utimes(2) after you're done reading.
Once this is done, your shell can do this on login:

    if ($st_size) {
	printf "You have %s mail.\n", $st_atime > $st_mtime ? "old" : "new";
    }

oops, that was in perl not C :-)  (i just wrote the perl translation 
to cmail and posted it to alt.sources)   you see what i mean though.

--tom

    Tom Christiansen                       {uunet,uiucdcs,sun}!convex!tchrist 
    Convex Computer Corporation                            tchrist@convex.COM
		 "EMACS belongs in <sys/errno.h>: Editor too big!"