Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932221AbbFHXbD (ORCPT ); Mon, 8 Jun 2015 19:31:03 -0400 Received: from mail-lb0-f180.google.com ([209.85.217.180]:35357 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753354AbbFHX1R (ORCPT ); Mon, 8 Jun 2015 19:27:17 -0400 From: Rasmus Villemoes To: Andrew Morton , Daniel Borkmann , Herbert Xu Cc: Joe Perches , Al Viro , Rasmus Villemoes , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/8] lib: string: Introduce strreplace Date: Tue, 9 Jun 2015 01:26:49 +0200 Message-Id: <1433806017-10823-2-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1433806017-10823-1-git-send-email-linux@rasmusvillemoes.dk> References: <1433806017-10823-1-git-send-email-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2408 Lines: 68 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 --- v2: spello fixed, parameters renamed 'old' and 'new' (just so the kernel doc aligns nicely, and because that's what python -c 'help(str.replace)' uses). Still EXPORT_SYMBOL, not inline (tried it, caused more bloat), still called strreplace. 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..a8d90db9c4b0 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); +char *strreplace(char *s, char old, char new); extern void kfree_const(const void *x); diff --git a/lib/string.c b/lib/string.c index bb3d4b6993c4..13d1e84ddb80 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 occurrences of character in string. + * @s: The string to operate on. + * @old: The character being replaced. + * @new: The character @old is replaced with. + * + * Returns pointer to the nul byte at the end of @s. + */ +char *strreplace(char *s, char old, char new) +{ + for (; *s; ++s) + if (*s == old) + *s = new; + return s; +} +EXPORT_SYMBOL(strreplace); -- 2.1.3 -- 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/