From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932810AbXCAANL (ORCPT ); Wed, 28 Feb 2007 19:13:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932813AbXCAANL (ORCPT ); Wed, 28 Feb 2007 19:13:11 -0500 Received: from crystal.sipsolutions.net ([195.210.38.204]:40286 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932810AbXCAANK (ORCPT ); Wed, 28 Feb 2007 19:13:10 -0500 Subject: [PATCH] make sscanf honor %n at end of input string From: Johannes Berg To: Linux Kernel list Content-Type: text/plain Date: Thu, 01 Mar 2007 01:12:31 +0100 Message-Id: <1172707951.11911.3.camel@johannes.berg> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I was playing with some code that sometimes got a string where a %n match should have been done where the input string ended, for example like this: sscanf("abc123", "abc%d%n", &a, &n); However, the scanf function in the kernel doesn't convert the %n in that case because it has already matched the complete input after %d. This patch changes that. Signed-off-by: Johannes Berg --- Shrug. My use case for this collapsed, but I figured having scanf doing that correctly might be a good thing. lib/vsprintf.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- wireless-dev.orig/lib/vsprintf.c 2007-03-01 00:28:31.776381760 +0100 +++ wireless-dev/lib/vsprintf.c 2007-03-01 00:59:33.256381760 +0100 @@ -825,6 +825,15 @@ int vsscanf(const char * buf, const char break; str = next; } + + /* Now we've come all the way through so either the input string or + * the format ended. In the former case, there can be a %n at the + * current position in the format that needs to be filled. */ + if (*fmt == '%' && *(fmt+1) == 'n') { + int *i = (int *)va_arg(args,int*); + *i = str - buf; + } + return num; }