Xref: utzoo comp.unix.questions:12826 comp.lang.c:17618
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!apple!amdahl!kucharsk
From: kucharsk@uts.amdahl.com (William Kucharski)
Newsgroups: comp.unix.questions,comp.lang.c
Subject: Re: lockfile/unix/c
Keywords: c, unix, lockf
Message-ID: <18gKx90ToP1010Y2K7U@amdahl.uts.amdahl.com>
Date: 13 Apr 89 05:32:19 GMT
References: <6307@homxc.ATT.COM>
Reply-To: kucharsk@amdahl.uts.amdahl.com (William Kucharski)
Organization: Amdahl Coup, UTS Products Hen House
Lines: 18

Calls to lockf(3C) must be made with a file descriptor opened to either
O_WRONLY or O_RDWR modes.

So, change your code to read:

    fd = open(FILENAME, O_CREAT | O_RDWR, 0666);
    lockf(fd, F_LOCK, (long)0);

Everything will work just fine.
-- 
					William Kucharski

ARPA: kucharsk@uts.amdahl.com
UUCP: ...!{ames,decwrl,sun,uunet}!amdahl!kucharsk

Disclaimer:  The opinions expressed above are my own, and may not agree with
	     those of any other sentient being, not to mention those of my 
	     employer.  So there.