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Date: Wed, 10 Jul 2002 18:48:30 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: [BUG]  open(): Opening with flags O_RDONLY | O_APPEND positions the file pointer at the end of the file
Message-ID: <20020710184830.J24137@cygbert.vinschen.de>
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References: <823876622 DOT 20020710153943 AT syntrex DOT com> <20020710163613 DOT GD10966 AT redhat DOT com>
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On Wed, Jul 10, 2002 at 12:36:13PM -0400, Chris Faylor wrote:
> On Wed, Jul 10, 2002 at 03:39:43PM +0200, Pavel Tsekov wrote:
> >Hello, there :)
> >
> >Attached is a testcase which displays the problem. On Linux it will
> >properly return 13, while on cygwin it returns 0.
> >
> >I found this while trying to understand why MC doesn't extract
> >properly files from say .zip files.
> >
> >I don't know exactly why they call O_RDONLY combined with O_APPEND but
> >I will mail the mc-devel list ASAP.
> >
> >Still according to the Linux man page and SUSv2, O_APPEND should be
> >taken into account only when writing to the file.
> >
> >Having in mind that fhandler_base::write() calls SetFilePointer
> >before each write, I wonder why fhandler_disk_base::open calls
> >SetFilePointer when it detects O_APPEND ?
> 
> Good question.

What if

 	fd = open(O_APPEND);
	pos = lseek(fd, 0, SEEK_CUR);

?  If open() doesn't move the pointer, `pos' is incorrectly set to 0.

Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin AT cygwin DOT com
Red Hat, Inc.

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