Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!voder!pyramid!ctnews!mitisft!kemnitz
From: kemnitz@mitisft.Convergent.COM (Gregory Kemnitz)
Newsgroups: comp.unix.questions
Subject: Re: truncating an open (locked) file
Summary: Close frees flock() locks by definition...
Keywords: truncate portable
Message-ID: <697@mitisft.Convergent.COM>
Date: 18 May 89 19:54:04 GMT
References: <269@sawmill.UUCP>
Distribution: comp
Organization: Convergent Technologies, San Jose, CA
Lines: 25

In article <269@sawmill.UUCP>, rjk@sawmill.UUCP (Richard Kuhns) writes:
< 
< [stuff deleted] 

< Don't close(2) the second file descriptor!  If you close *either* file
< descriptor, the lock goes away.  At least, it does on a 3B1 running 3.51 --
< is this behaviour standard?

Yes.  close() will free any locks on files.

< 
< So now, I have a slight variation of my original question:  Does anyone
< have a portable way to truncate (to size 0) an open file, which both
< maintains an existing lock on the file and doesn't waste a file
< descriptor?
< 

No.  There is not.  Only hope:  there is a truncate() and ftruncate() call
in POSIX, so there will be one in Sys V.4.

-- 
----------------------------------+--------------------------------------
Greg Kemnitz                      |  "He who does not understand baseball
kemnitz@Convergent.COM            |   will never understand America"
                                  |  --Tocqueville