Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!usc!hacgate!ashtate!dbase!awd
From: awd@dbase.A-T.COM (Alastair Dallas)
Newsgroups: comp.databases
Subject: Re: File locking with DbaseIII/IV
Summary: Can't get there from here.
Message-ID: <1991Jun3.031554.20350@dbase.A-T.COM>
Date: 3 Jun 91 03:15:54 GMT
References: <1991May24.224602.19130@netcom.COM>
Organization: Ashton-Tate, Inc.
Lines: 28

In article <1991May24.224602.19130@netcom.COM>, rsinger@netcom.COM (Richard Singer) writes:
> I am writing an application which needs to share dbase files  with Dbase 
> III/III+/IV over a network.  Does anyone know how these dbase versions 
> lock files/records? or any reference which might describe this.

This question was asked and answered a few months ago.  Sorry, but you
can't easily do it--the locking protocol is proprietary to Ashton-Tate,
trade secrets and all that.  If you or someone else figures it out by
reverse-engineering, that's in violation of the license agreement.  

I may be completely wrong in stating 1) Ashton-Tate's position, 2) the
legalities involved, or 3) the existing situation with respect to the
number of people actively disseminating the information.  Obviously,
I don't think I'm wrong, and I'm one of the "experts" that A-T legal
would naturally ask about locking trade secrets and that's what I'd
tell them.

Sorry it's no help.  My advice is let your app write transaction files
which the dBASE app batch updates from periodically in exclusive mode.

/alastair/



-- 
|Disclaimer: I am speaking for myself, not as a spokesman for Ashton-Tate,
|which does not monitor my outbursts here.  I reserve all rights to my
|opinions in terms of commercial endorsements.