Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!VAX1.CC.UAKRON.EDU!mcs.kent.edu!usenet.ins.cwru.edu!ncoast!allbery
From: allbery@NCoast.ORG (Brandon S. Allbery KB8JRR)
Newsgroups: comp.lang.perl
Subject: Re: While learning PERL... a suggestion
Message-ID: <1991Jan22.174840.21465@NCoast.ORG>
Date: 22 Jan 91 17:48:40 GMT
References: <1991Jan21.214453.25039@convex.com> <119440@uunet.UU.NET> <1991Jan22.054732.14797@convex.com>
Reply-To: allbery@ncoast.ORG (Brandon S. Allbery KB8JRR)
Followup-To: comp.lang.perl
Organization: North Coast Computer Resources (ncoast)
Lines: 27

As quoted from <1991Jan22.054732.14797@convex.com> by tchrist@convex.COM (Tom Christiansen):
+---------------
| With NFS, all bets are off: the same file may be created and deleted
| more than once, with success returned to both.  It's horrid, I know, but
| it's there.  Too many of us use NFS to rely on this.
| 
| Anyway aren't you "supposed" to use link, not creat, for creating
| lock files of this nature?
+---------------

The System III/V manpage for open(2) strongly implies (if not actually says
--- I don't know if the Xenix manpage on here reflects the real System V one
or not) that open(..., O_CREAT|O_EXCL, ...) is the "proper" way to create lock
files.  (This despite certain problems like root being able to create it
anyway.)  Nevertheless, since it's documented as being a way of doing it,
there are programs (not to mention programmers, although I'm not one of them)
that do this.

Also, RFS appears to get this right --- and we have more systems using RFS
than NFS.

++Brandon
-- 
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