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Path: utzoo!mnetor!seismo!ll-xn!cit-vax!mangler
From: mangler@cit-vax.Caltech.Edu (System Mangler)
Newsgroups: comp.unix.wizards
Subject: Re: A synchronization problem with 4.3BSD MAIL ??
Message-ID: <3092@cit-vax.Caltech.Edu>
Date: Fri, 26-Jun-87 21:30:08 EDT
Article-I.D.: cit-vax.3092
Posted: Fri Jun 26 21:30:08 1987
Date-Received: Sat, 27-Jun-87 11:50:07 EDT
References: <375@mit-caf.UUCP>
Organization: California Institute of Technology
Lines: 19
Keywords: mail bug  4.3bsd ??
Summary: quit command is the window of vulnerability

In article <375@mit-caf.UUCP>, vanni@mit-caf.UUCP (Giovanni Berti) writes:
>	>>>> You might actually be loosing mail too <<<<
>
>	The only reason why we saw the problem is because the
>	user has biff set (biff yes) and stays loged on for several

[I'm using 4.2bsd /usr/ucb/mail]
Any mail received between the time you give the "quit" (or ^D)
command and when it finishes writing out $MAIL will be *lost*.
This window of vulnerability is particularly troublesome if
one's mail file is large, or the machine is slow, or you get
a lot of mail.	I lost two pieces of mail like that today.

Mail received while the program is reading in $MAIL will be
duplicated.  One suspects that there is no locking at all.

I never knew how much mail I was missing until I started using biff.

Don Speck   speck@vlsi.caltech.edu  {seismo,rutgers,ames}!cit-vax!speck