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From: tenney@well.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: Truncating MS-DOS files
Message-ID: <2596@well.UUCP>
Date: Mon, 16-Feb-87 05:40:16 EST
Article-I.D.: well.2596
Posted: Mon Feb 16 05:40:16 1987
Date-Received: Tue, 17-Feb-87 02:43:59 EST
References: <1987Feb15.123004.21019@gpu.utcs.toronto.edu> <4141@diamond.Diamond.BBN.COM>
Reply-To: tenney@well.UUCP (Glenn S. Tenney)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 18

In article <4141@diamond.Diamond.BBN.COM> mlandau@Diamond.BBN.COM (Matt Landau) writes:
>If you seek to a file position, write zero bytes, and close the file, the
>file is truncated at the seek position.  This behavior is consistent in all
>versions of PC- and MS-DOS from 2.0 to 3.2, but since it is not documented,
>there's no guarantee it won't go away sometime in the future.
>...
That is exactly the way it is documented!
RTFM:  function 28 Random Block Write
   ...  If CX is zero upon entry, no records are written, but the
        file is set to the length specified by the random record field,
        whether longer or shorter than the current file size.
!!!

-- Glenn Tenney 
UUCP: {hplabs,glacier,lll-crg,ihnp4!ptsfa}!well!tenney
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As Alphonso Bodoya would say... (tnx boulton)
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