From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752733AbaHKHiV (ORCPT ); Mon, 11 Aug 2014 03:38:21 -0400 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:35479 "EHLO lgemrelse7q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752040AbaHKHiU (ORCPT ); Mon, 11 Aug 2014 03:38:20 -0400 X-Original-SENDERIP: 10.177.220.181 X-Original-MAILFROM: namhyung@gmail.com From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Minchan Kim , Peter Zijlstra , Ingo Molnar , Paul Mackerras , Namhyung Kim , LKML , Jiri Olsa , David Ahern Subject: Re: [PATCH 1/2] perf tools: Ensure --symfs ends with '/' References: <1406251908-8195-1-git-send-email-namhyung@kernel.org> <20140729050246.GC22707@bbox> <20140729123305.GO7831@kernel.org> <87ppgnhge3.fsf@sejong.aot.lge.com> <20140730151932.GS7831@kernel.org> <20140730205521.GU7831@kernel.org> <87ha1ygnn3.fsf@sejong.aot.lge.com> <20140731122621.GV7831@kernel.org> <87d2clgkv9.fsf@sejong.aot.lge.com> <20140801201538.GA13375@kernel.org> Date: Mon, 11 Aug 2014 16:38:17 +0900 In-Reply-To: <20140801201538.GA13375@kernel.org> (Arnaldo Carvalho de Melo's message of "Fri, 1 Aug 2014 17:15:38 -0300") Message-ID: <87zjfbfpcm.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnaldo, On Fri, 1 Aug 2014 17:15:38 -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, Aug 01, 2014 at 08:38:02AM +0900, Namhyung Kim escreveu: >> Hi Arnaldo, >> >> On Thu, 31 Jul 2014 09:26:21 -0300, Arnaldo Carvalho de Melo wrote: >> > Em Thu, Jul 31, 2014 at 01:25:52PM +0900, Namhyung Kim escreveu: >> >> Are you still against my approach - adding '/' at the end of the symfs >> >> string itself? It seems that mine is simpler and shorter. > >> > Yes, I am. > >> > We are not just concatenating two strings, we are joining two path >> > components. > >> > I think it is more clear and elegant to do it as python os.path.join() >> > does. > >> Then I think you also need to care about trailing and leading '/' in the >> components so that, say, joining '/home/' and '/namhyung/' can result in >> '/home/namhyung/' not '/home///namhyung/'. > > Well, "/home/namhyung/" is the same as "/home///namhyung/" for POSIX: > http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_266 > > So, when we can easily avoid it, no use to have a sequence of slashes, > but otherwise it is harmless. Yes, I know it's supported. But I think it'd be better off avoiding it in order to be an elegant path joiner. :) > >> Btw, it seems like python's os.path.join() just use latter if it's an >> absolute path. >> >> $ python >> Python 2.7.3 (default, Jul 24 2012, 10:05:38) >> [GCC 4.7.0 20120507 (Red Hat 4.7.0-5)] on linux2 >> Type "help", "copyright", "credits" or "license" for more information. >> >>> import os.path >> >>> os.path.join('/home/', '/namhyung/') >> '/namhyung/' > > Interesting, wonder what is the rationale for that or if this is a bug. Hmm.. pydoc os.path.join says below: os.path.join = join(a, *p) Join two or more pathname components, inserting '/' as needed. If any component is an absolute path, all previous path components will be discarded. An empty last part will result in a path that ends with a separator. Thanks, Namhyung