Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!portal!cup.portal.com!Devin_E_Ben-Hur
From: Devin_E_Ben-Hur@cup.portal.com
Newsgroups: comp.sys.ibm.pc
Subject: Re: Open files when PC goes down
Message-ID: <15982@cup.portal.com>
Date: 18 Mar 89 22:31:18 GMT
References: <1939@holos0.UUCP>
Distribution: usa
Organization: The Portal System (TM)
Lines: 20

Len Reed asks about how to assure that data written to an open file is
recoverable after a system crash before the file close.

The accepted procedure for this is to duplicate the file handle and close
the duplicate.  This will flush internal dos buffers to disk and write
the FAT and directory info associated with the file, but will leave the
original file handle open and correctly positioned.  Here's an asm
fragment to do this:

	mov	bx,file_handle
	mov	ah,045h		;duplicate handle func
	int	021h
	jc	error
	xchg	bx,ax		;move duplicate handle to bx
	mov	ah,03Eh		;close file func
	int	021h
	jc	error

Devin_Ben-Hur@Cup.Portal.Com
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