From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Jackson Subject: Re: [4/5] Add option for hardlinkable cache of extracted blobs Date: Sun, 17 Apr 2005 12:25:17 -0700 Organization: SGI Message-ID: <20050417122517.4b12faea.pj@sgi.com> References: <20050417174736.GA1461@pasky.ji.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: barkalow@iabervon.org, git@vger.kernel.org X-From: git-owner@vger.kernel.org Sun Apr 17 21:24:02 2005 Return-path: Received: from vger.kernel.org ([12.107.209.244]) by ciao.gmane.org with esmtp (Exim 4.43) id 1DNFMq-0002bm-PT for gcvg-git@gmane.org; Sun, 17 Apr 2005 21:23:41 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261427AbVDQT1B (ORCPT ); Sun, 17 Apr 2005 15:27:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261428AbVDQT06 (ORCPT ); Sun, 17 Apr 2005 15:26:58 -0400 Received: from omx3-ext.sgi.com ([192.48.171.20]:60098 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S261427AbVDQTZi (ORCPT ); Sun, 17 Apr 2005 15:25:38 -0400 Received: from cthulhu.engr.sgi.com (cthulhu.engr.sgi.com [192.26.80.2]) by omx3.sgi.com (8.12.11/8.12.9/linux-outbound_gateway-1.1) with ESMTP id j3HJmwnB010504; Sun, 17 Apr 2005 12:49:01 -0700 Received: from vpn2 (mtv-vpn-hw-pj-2.corp.sgi.com [134.15.25.219]) by cthulhu.engr.sgi.com (SGI-8.12.5/8.12.5) with SMTP id j3HJPLlU15479253; Sun, 17 Apr 2005 12:25:22 -0700 (PDT) To: Petr Baudis In-Reply-To: <20050417174736.GA1461@pasky.ji.cz> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i686-pc-linux-gnu) Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Petr wrote: > BTW, I'd just use access(F_OK) instead of stat() it I don't care about That's a bad habit to get into. access(2) checks with the process's real uid and gid, rather than with the effective ids as is done when actually attempting an operation. This is to allow set-UID programs to easily determine the invoking user's authority. Using access(2) when it shouldn't be used is a common source of bugs. I recommend _only_ using it when you require exactly the above real vs. effective id behaviour. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.650.933.1373, 1.925.600.0401