Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932468Ab2HFSsW (ORCPT ); Mon, 6 Aug 2012 14:48:22 -0400 Received: from imp01.mtu.ru ([62.5.255.10]:41149 "EHLO imp01.mtu.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932455Ab2HFSsT (ORCPT ); Mon, 6 Aug 2012 14:48:19 -0400 X-Spam-Flag: NO Message-ID: <50201156.30704@pavlinux.ru> Date: Mon, 06 Aug 2012 22:47:50 +0400 From: Pavel Vasilyev Reply-To: pavel@pavlinux.ru Organization: Pavlinux. Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.6esrpre) Gecko/20120713 Thunderbird/10.0.6 MIME-Version: 1.0 To: Alan Stern CC: Pavel Machek , Len Brown , linux-acpi@vger.kernel.org, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Len Brown Subject: Re: [linux-pm] [PATCH] ACPI: replace strlen("string") with sizeof("string") -1 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1659 Lines: 44 06.08.2012 20:28, Alan Stern пишет: > On Mon, 6 Aug 2012, Pavel Vasilyev wrote: > >> 06.08.2012 18:36, Alan Stern пишет: >>> On Mon, 6 Aug 2012, Pavel Machek wrote: >>> >>>> On Thu 2012-07-26 21:39:38, Len Brown wrote: >>>>> ...both give the number of chars in the string >>>>> without the '\0', as strncmp() wants, >>>>> but sizeof() is compile-time. >>>> >>>> What about introducing something like streq() to do this >>>> automatically? This is ugly.... >>>> >>>> #define streq(a, b) ... if (_buildin_constant(b)) ... >>>> >>>> ? >>>> >>>>> - if (!strncmp(val, "enable", strlen("enable"))) { >>>>> + if (!strncmp(val, "enable", sizeof("enable") - 1)) { >>> >>> While you're at it, there's no point using strncmp when you know the >>> length of one of the strings beforehand. Just use memcmp, and don't >>> subtract 1 from the sizeof value. >> >> http://www.gossamer-threads.com/lists/engine?do=post_attachment;postatt_id=41157;list=linux > > Interestingly, many (all?) of the changes in that patch are wrong > because they don't try to match the terminating '\0'. As a result, > they will match against extensions of the target string as well as the > target string itself. > strNcmp compare N bytes - http://lxr.linux.no/#linux+v3.5/lib/string.c#L270 memcmp compare N bytes - http://lxr.linux.no/#linux+v3.5/lib/string.c#L651 -- Pavel. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/