From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753667AbbFDJlx (ORCPT ); Thu, 4 Jun 2015 05:41:53 -0400 Received: from mail-la0-f50.google.com ([209.85.215.50]:33396 "EHLO mail-la0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752619AbbFDJh3 (ORCPT ); Thu, 4 Jun 2015 05:37:29 -0400 From: Rasmus Villemoes To: Andrew Morton , Daniel Borkmann , Herbert Xu Cc: Rasmus Villemoes , linux-kernel@vger.kernel.org Subject: [RFC/PATCH 1/8] lib: string: Introduce strreplace Date: Thu, 4 Jun 2015 11:37:08 +0200 Message-Id: <1433410636-26812-2-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1433410636-26812-1-git-send-email-linux@rasmusvillemoes.dk> References: <1433410636-26812-1-git-send-email-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Strings are sometimes sanitized by replacing a certain character (often '/') by another (often '!'). In a few places, this is done the same way Schlemiel the Painter would do it. Others are slightly smarter but still do multiple strchr() calls. Introduce strreplace() to do this using a single function call and a single pass over the string. One would expect the return value to be one of three things: void, s, or the number of replacements made. I chose the fourth, returning a pointer to the end of the string. This is more likely to be useful (for example allowing the caller to avoid a strlen call). Signed-off-by: Rasmus Villemoes --- include/linux/string.h | 1 + lib/string.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index e40099e585c9..4f09e41c7169 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -111,6 +111,7 @@ extern int memcmp(const void *,const void *,__kernel_size_t); extern void * memchr(const void *,int,__kernel_size_t); #endif void *memchr_inv(const void *s, int c, size_t n); +extern char *strreplace(char *s, char bad, char good); extern void kfree_const(const void *x); diff --git a/lib/string.c b/lib/string.c index bb3d4b6993c4..ef52e86f6b87 100644 --- a/lib/string.c +++ b/lib/string.c @@ -849,3 +849,20 @@ void *memchr_inv(const void *start, int c, size_t bytes) return check_bytes8(start, value, bytes % 8); } EXPORT_SYMBOL(memchr_inv); + +/** + * strreplace - Replace all occurences of character in string + * @s: The string to operate on + * @bad: The character being replaced + * @good: The character @bad is replaced with. + * + * Returns pointer to the nul byte at the end of @s. + */ +char *strreplace(char *s, char bad, char good) +{ + for (; *s; ++s) + if (*s == bad) + *s = good; + return s; +} +EXPORT_SYMBOL(strreplace); -- 2.1.3