From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752795AbZH1M6Y (ORCPT ); Fri, 28 Aug 2009 08:58:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752595AbZH1M6X (ORCPT ); Fri, 28 Aug 2009 08:58:23 -0400 Received: from qmta05.emeryville.ca.mail.comcast.net ([76.96.30.48]:57500 "EHLO QMTA05.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752535AbZH1M6X (ORCPT ); Fri, 28 Aug 2009 08:58:23 -0400 Message-ID: <4A97D471.5030100@byu.net> Date: Fri, 28 Aug 2009 06:58:25 -0600 From: Eric Blake User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.23) Gecko/20090812 Thunderbird/2.0.0.23 Mnenhy/0.7.6.666 MIME-Version: 1.0 To: Florian Weimer CC: Davide Libenzi , Linux Kernel Mailing List , bug-coreutils@gnu.org, bug-gnulib@gnu.org, Ulrich Drepper , Ingo Molnar Subject: Re: [PATCH] open: introduce O_NOSTD References: <4A9285FC.8000606@byu.net> <1251202593-3676-1-git-send-email-ebb9@byu.net> <4A968FF8.8050109@byu.net> <82k50puxx8.fsf@mid.bfk.de> <4A97D16D.5060003@byu.net> <82ocq0p0ba.fsf@mid.bfk.de> In-Reply-To: <82ocq0p0ba.fsf@mid.bfk.de> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Florian Weimer on 8/28/2009 6:52 AM: >> If the caller requested O_CLOEXEC, then your version takes 3, 5, or >> 7 syscalls depending on how many std fds were closed, while my >> version takes 3 syscalls regardless of how many std fds were closed. > > I really don't see a way around that. You can't pick a descriptor and > hope that it's unused. fcntl(,F_DUPFD,3) is NOT like dup2. It picks the next available descriptor that is at least 3. - -- Don't work too hard, make some time for fun as well! Eric Blake ebb9@byu.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkqX1HEACgkQ84KuGfSFAYAzYQCgnwad5k39bZJqw3Wg1vMED/Fd zjYAmwenJlImBUE33geRdHC6aoVSx7JG =omNI -----END PGP SIGNATURE-----