Path: utzoo!attcan!uunet!mcsun!ukc!kl-cs!jonathan
From: jonathan@cs.keele.ac.uk (Jonathan Knight)
Newsgroups: comp.mail.misc
Subject: Re: Checking for new mail
Message-ID: <736@kl-cs.UUCP>
Date: 24 Aug 89 22:58:52 GMT
References: <1117@ispi.UUCP>
Organization: University of Keele, England
Lines: 39

From article <1117@ispi.UUCP>, by jbayer@ispi.UUCP (Jonathan Bayer):

There are several techniques for finding out if new mail has
arrived.  Firstly, you can place a filter somewhere so that it
gets run whenever new mail arrives.  This method has been
mentioned earlier for use with sendmail.  All you have to do is
create a file called .forward with the line like this:
	"| /fs/cs/jonathan/inboundmail"
and then write a short shell script called
/fs/cs/jonathan/inboundmail like this:
	#! /bin/sh
	/bin/mail -d jonathan
	echo "New mail has just been delivered" > /dev/ttyk5

This will have the desired effect if you were me and you always
used /dev/ttyk5 to log in, anyway, the idea is there.

Another method is to check the users mailbox periodically to see
if the access times have changed.  This is used by the shell's
that say "You have new mail".  All they do is remember when the
last modification time was, and then check it every now and again
until it changes.  Various programs will run in the background and
check this every minute, "newmail" which is part of the elm system
springs to mind.

A third method is to deduce when new mail has arrived by looking
at the access and modification times of the mailbox.  I have
written a program called cmail which will report whether new mail
has arrived in a users mailbox.  From studying the effects of
elm, mail, mailx, sendmail and /bin/mail I developed an algorithm
to do this.  I have posted it to comp.sources.unix some weeks ago
so I suppose it will appear soon.

Does this answer the original question?
-- 
  ______    JANET :jonathan@uk.ac.keele.cs     Jonathan Knight,
    /       BITNET:jonathan%cs.kl.ac.uk@ukacrl Department of Computer Science
   / _   __ other :jonathan@cs.keele.ac.uk     University of Keele, Keele,
(_/ (_) / / UUCP  :...!ukc!kl-cs!jonathan      Staffordshire.  ST5 5BG.  U.K.