Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!ogicse!pdxgate!eecs!kirkenda
From: kirkenda@eecs.cs.pdx.edu (Steve Kirkendall)
Newsgroups: comp.os.minix
Subject: Re: File locking in MINIX and UNIX
Message-ID: <1661@pdxgate.UUCP>
Date: 18 Feb 91 20:26:58 GMT
References: <39313@cup.portal.com>
Sender: news@pdxgate.UUCP
Reply-To: kirkenda@eecs.UUCP (Steve Kirkendall)
Organization: Portland State University, Portland, OR
Lines: 17

In article <39313@cup.portal.com> Kenyon_F_Karl@cup.portal.com writes:
>Thus, my immediate problem is that rebooting the system while 'elvis' was 
>still running left a temporary file in /usr/tmp. When 'elvis' found the 
>file after the reboot, it thought that the file was still being edited. 
>Running the command 'rm /usr/tmp/*' as 'superuser' removed the temp file. 

The file in /usr/tmp is more than just a lock file.  It is used to contain
a copy of the file being edited, with extra space inserted to make editing
faster.  Whenever Elvis dies for any reason (system crash, elvis bug, lost
carrier, power failure, etc.) the "virec" program can be used to recover the
changed text that is stored in that temporary file.

The fact that this file acts as a lock file is really just an unfortunate
consequense of the method Elvis uses for filename generation.  I plan to
remove that limitation soon.
-------------------------------------------------------------------------------
Steve Kirkendall     kirkenda@cs.pdx.edu      Grad student at Portland State U.