Path: utzoo!attcan!uunet!zaphod.mps.ohio-state.edu!usc!ucsd!ames!sgi!shinobu!odin!lavalite.asd.sgi.com!rlb
From: rlb@lavalite.asd.sgi.com (Robert Brown)
Newsgroups: comp.sys.sgi
Subject: Re: Silly error with flock
Message-ID: <1991Jan9.163014.2637@odin.corp.sgi.com>
Date: 9 Jan 91 16:30:14 GMT
References: <1991Jan9.030948.18665@ccu1.aukuni.ac.nz>
Sender: news@odin.corp.sgi.com (Net News)
Reply-To: rlb@lavalite.asd.sgi.com (Robert Brown)
Distribution: comp
Organization: Silicon Graphics, Inc., Mountain View, CA.
Lines: 21

On the bottom of my copy of the flock manual page is the following:

     Unlike BSD flock(2), attempts to acquire an exclusive lock on an fd
     opened for reading but not writing will fail with EBADF, as will attempts
     to acquire a shared lock on a write-only fd.

Also, your test

      if ( lock <= 0) perror("open");

should be

      if ( lock < 0) perror("open");

but that's unrelated to the condition you asked about

Hope that helps!

Bob Brown
------------------------------------------------------------------
Silicon Graphics, Inc.  Advanced Systems Division