From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756575Ab0AOEAg (ORCPT ); Thu, 14 Jan 2010 23:00:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756460Ab0AOD7s (ORCPT ); Thu, 14 Jan 2010 22:59:48 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:36023 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754256Ab0AOD6z (ORCPT ); Thu, 14 Jan 2010 22:58:55 -0500 X-Authority-Analysis: v=1.0 c=1 a=RRHqD-2QBUoA:10 a=omOdbC7AAAAA:8 a=pGLkceISAAAA:8 a=meVymXHHAAAA:8 a=FGfIGzqGBb_-eyKQmZ0A:9 a=eeM_ybOtwOf8Kz8GtlUA:7 a=aDmiRSmc8HuFVIdYLb9N9JOi_TwA:4 a=MSl-tDqOz04A:10 a=jeBq3FmKZ4MA:10 a=rfSSAgpB8YlTvswe:21 a=EJ7AwCN74JD5_Yzt:21 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.89.75 Message-Id: <20100115035853.256010100@goodmis.org> User-Agent: quilt/0.48-1 Date: Thu, 14 Jan 2010 22:57:31 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Li Zefan , Frederic Weisbecker Subject: [PATCH 5/8] lib: Introduce strnstr() References: <20100115035726.462940848@goodmis.org> Content-Disposition: inline; filename=0005-lib-Introduce-strnstr.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Li Zefan It differs strstr() in that it limits the length to be searched in the first string. Signed-off-by: Li Zefan LKML-Reference: <4B4E8743.6030805@cn.fujitsu.com> Acked-by: Frederic Weisbecker Signed-off-by: Steven Rostedt --- include/linux/string.h | 5 ++++- lib/string.c | 27 ++++++++++++++++++++++++++- 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/include/linux/string.h b/include/linux/string.h index 651839a..a716ee2 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -72,7 +72,10 @@ static inline __must_check char *strstrip(char *str) } #ifndef __HAVE_ARCH_STRSTR -extern char * strstr(const char *,const char *); +extern char * strstr(const char *, const char *); +#endif +#ifndef __HAVE_ARCH_STRNSTR +extern char * strnstr(const char *, const char *, size_t); #endif #ifndef __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); diff --git a/lib/string.c b/lib/string.c index 9f75b4e..a1cdcfc 100644 --- a/lib/string.c +++ b/lib/string.c @@ -667,7 +667,7 @@ EXPORT_SYMBOL(memscan); */ char *strstr(const char *s1, const char *s2) { - int l1, l2; + size_t l1, l2; l2 = strlen(s2); if (!l2) @@ -684,6 +684,31 @@ char *strstr(const char *s1, const char *s2) EXPORT_SYMBOL(strstr); #endif +#ifndef __HAVE_ARCH_STRNSTR +/** + * strnstr - Find the first substring in a length-limited string + * @s1: The string to be searched + * @s2: The string to search for + * @len: the maximum number of characters to search + */ +char *strnstr(const char *s1, const char *s2, size_t len) +{ + size_t l1 = len, l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + while (l1 >= l2) { + l1--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} +EXPORT_SYMBOL(strnstr); +#endif + #ifndef __HAVE_ARCH_MEMCHR /** * memchr - Find a character in an area of memory. -- 1.6.5