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Path: utzoo!lsuc!dave
From: dave@lsuc.UUCP
Newsgroups: comp.unix.wizards
Subject: Re: How are mailfiles locked under 4.n and System III/V?
Message-ID: <1792@lsuc.UUCP>
Date: Thu, 14-May-87 21:13:05 EDT
Article-I.D.: lsuc.1792
Posted: Thu May 14 21:13:05 1987
Date-Received: Sat, 16-May-87 08:29:56 EDT
References: <7384@boring.mcvax.cwi.nl> <12733@teknowledge-vaxc.ARPA>
Reply-To: dave@lsuc.UUCP (David Sherman)
Organization: Law Society of Upper Canada, Toronto
Lines: 13
Summary: v7 uses chmod $MAIL; 4.1BSD uses /usr/spool/mail/username.lock

We run v7 mail as our mail delivery agent, and 4.1BSD Mail (modified
to suit our needs) for interactive reading & sending.  I just went
through the exercise of giving them the same locking mechanism, after
getting bitten once too often and losing mail.

v7 mail locks by turning on the "other x" bit of the file with
chmod(2) (i.e., st_mode|01).  4.1BSD Mail locks by link(2)'ing to
/usr/spool/mail/username.lock.

David Sherman
The Law Society of Upper Canada
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