X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=-6.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Message-ID: <4BB4CAFE.5070605@redhat.com> Date: Thu, 01 Apr 2010 10:34:06 -0600 From: Eric Blake User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc12 Lightning/1.0b1 Thunderbird/3.0.3 MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: fopen with "a+" does not respect setting file read position to start of file References: <4BB482FA.3030201@ltu.se> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig944A91C66923355F862917B1" X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com --------------enig944A91C66923355F862917B1 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable On 04/01/2010 05:53 AM, Matthias Andree wrote: >> Well if that worked previously it was a bug. >=20 > Not a Cygwin defect, but an application bug, and what Gavin named "work > around" is actually the right fix. >=20 > POSIX explicitly states that the initial position beginning/end of file > in append mode is implementation-defined, and the Cygwin documentation > doesn't make promises either way. Linux and FreeBSD document BOF and > EOF, respectively. I agree that it is not a cygwin bug. And I actually prefer Linux' interpretation of BOF, since it matches with the POSIX requirement that open(,O_APPEND|O_RDWR) be positioned at offset 0 and not at the end (it is only fopen that is allowed, but not required, to be at the end). In fact, the release of m4 1.4.10 worked on cygwin and Linux but was broken on BSD because of this very portability pitfall. --=20 Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org --------------enig944A91C66923355F862917B1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/ iEYEARECAAYFAku0ywEACgkQ84KuGfSFAYBP4ACfV1BGi7sPML01jLpul/N3OQSP 8ikAn0NarTjKWNVdDXQs5oqZ6ekOtIH/ =0YgL -----END PGP SIGNATURE----- --------------enig944A91C66923355F862917B1--