X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=Vt0K3DR9SXGhNSlKNzxTtuw53FDiO1scuxiOSdAauXh9jlZy3RURL
	u5OpOhLkLVoJ16wz3rPqX02LnVMHegxf7d2eDwN21fpuIxaxV7r80Y6Wt00UJALf
	wL0MP8h7/zqmGj6cKwuJDiaLTXw3KVu2liUvX3kRGUAL8lo/L6Txfg=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; s=default;
	bh=jn+Z8xPRZ9VqiK5oNCibVphI/ns=; b=x0DKsjtm7Fa/KNpnFOnq9ADuNSbw
	eQdZnfJxImU608vi4FI51Ed6HTjr/UsiSvUUeuNICTAh89quRG306YMoTPmw/Z28
	vWjq1dI+JblkWY/lncRUipL3fkXsF86E08vE5yBIInGgcEaloi5UdvYjlymAZwOg
	iOVyAcroscEh+qw=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Virus-Found:	No
X-Spam-SWARE-Status:	No, score=-5.9 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.2
X-HELO:	calimero.vinschen.de
Date:	Fri, 28 Mar 2014 10:31:10 +0100
From:	Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: open(O_RDWR) and lseek() fail
Message-ID:	<20140328093110.GA23367@calimero.vinschen.de>
Reply-To:	cygwin AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
References:	<op DOT xderrfffdyj81a AT monster DOT itedn32a DOT localdomain> <5334EF41 DOT 50809 AT redhat DOT com> <op DOT xde3qaa3dyj81a AT monster DOT itedn32a DOT localdomain>
MIME-Version:	1.0
In-Reply-To:	<op.xde3qaa3dyj81a@monster.itedn32a.localdomain>
User-Agent:	Mutt/1.5.21 (2010-09-15)

--J/dobhs11T7y2rNN
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Mar 28 13:48, Roy wrote:
> On Fri, 28 Mar 2014 11:40:49 +0800, Eric Blake <eblake AT redhat DOT com> wrote:
>=20
> >On 03/27/2014 07:29 PM, Roy wrote:
> >>Hello list,
> >>
> >>I wonder why lseek(SEEK_CUR) on open(O_RDWR) fails with errno=3D22, the
> >>code works on Linux:
> >>
> >>#include <stdio.h>
> >>#include <errno.h>
> >>#include <stdlib.h>
> >>#include <fcntl.h>
> >>int main(int argc, char** argv){
> >
> >Where's #include <unistd.h>?  It fails because you are missing the
> >prototype for lseeks, which means that the C compiler is trying to call
> >it with 'int offset' instead of 'off_t offset'.  Compile with -Wall.
> >
> >>
> >>Whats wrong with cygwin?
> >
> >Rather, fix the bugs in your code, and let the compiler help you.
> >
>=20
> Got it, but why enforcing the use of off_t here?
> I'm not going to use 64bit offsets.

It doesn't matter what you use, it matters what the function expects.
lseek expects off_t per POSIX:

http://pubs.opengroup.org/onlinepubs/9699919799/functions/lseek.html

and off_t is defined as 64 bit type.


Corinna

--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--J/dobhs11T7y2rNN
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
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=Se4x
-----END PGP SIGNATURE-----

--J/dobhs11T7y2rNN--

- Raw text -