From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753319AbbFDK4T (ORCPT ); Thu, 4 Jun 2015 06:56:19 -0400 Received: from smtprelay0150.hostedemail.com ([216.40.44.150]:38484 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753123AbbFDK4L (ORCPT ); Thu, 4 Jun 2015 06:56:11 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::,RULES_HIT:41:355:379:541:599:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2559:2562:2689:2828:3138:3139:3140:3141:3142:3354:3622:3865:3866:3867:3868:3870:3871:3872:3873:4321:5007:6261:7875:7903:8531:8660:10004:10400:10848:11232:11658:11914:12296:12517:12519:12740:13069:13148:13230:13311:13357:14096:14097:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: hot10_359c8cb23b033 X-Filterd-Recvd-Size: 2793 Message-ID: <1433415367.4861.152.camel@perches.com> Subject: Re: [RFC/PATCH 1/8] lib: string: Introduce strreplace From: Joe Perches To: Rasmus Villemoes Cc: Andrew Morton , Daniel Borkmann , Herbert Xu , linux-kernel@vger.kernel.org Date: Thu, 04 Jun 2015 03:56:07 -0700 In-Reply-To: <1433410636-26812-2-git-send-email-linux@rasmusvillemoes.dk> References: <1433410636-26812-1-git-send-email-linux@rasmusvillemoes.dk> <1433410636-26812-2-git-send-email-linux@rasmusvillemoes.dk> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.12.11-0ubuntu3 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2015-06-04 at 11:37 +0200, Rasmus Villemoes wrote: > 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). You used in one of the follow-on patches too. > diff --git 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 occurrences > + * @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); Seems sensible, but the name maybe could be be more explicit as strreplace seems like it should more like a string substitution rather than a char substitution. Maybe strsubstchr or something like it (strtranschr?) Because it's so tiny, perhaps this could be inline instead of EXPORT_SYMBOL. Maybe from and to instead of good and bad arguments.