105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* c-strncasecmp.c -- case insensitive string comparator in C locale 205436638acc7c010349a69c3395f1a57c642dc62Ying Wang Copyright (C) 1998-1999, 2005-2006, 2009-2012 Free Software Foundation, Inc. 305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 405436638acc7c010349a69c3395f1a57c642dc62Ying Wang This program is free software; you can redistribute it and/or modify 505436638acc7c010349a69c3395f1a57c642dc62Ying Wang it under the terms of the GNU General Public License as published by 605436638acc7c010349a69c3395f1a57c642dc62Ying Wang the Free Software Foundation; either version 3, or (at your option) 705436638acc7c010349a69c3395f1a57c642dc62Ying Wang any later version. 805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 905436638acc7c010349a69c3395f1a57c642dc62Ying Wang This program is distributed in the hope that it will be useful, 1005436638acc7c010349a69c3395f1a57c642dc62Ying Wang but WITHOUT ANY WARRANTY; without even the implied warranty of 1105436638acc7c010349a69c3395f1a57c642dc62Ying Wang MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1205436638acc7c010349a69c3395f1a57c642dc62Ying Wang GNU General Public License for more details. 1305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1405436638acc7c010349a69c3395f1a57c642dc62Ying Wang You should have received a copy of the GNU General Public License 1505436638acc7c010349a69c3395f1a57c642dc62Ying Wang along with this program; if not, see <http://www.gnu.org/licenses/>. */ 1605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1705436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <config.h> 1805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1905436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Specification. */ 2005436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include "c-strcase.h" 2105436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2205436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <limits.h> 2305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2405436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include "c-ctype.h" 2505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2605436638acc7c010349a69c3395f1a57c642dc62Ying Wangint 2705436638acc7c010349a69c3395f1a57c642dc62Ying Wangc_strncasecmp (const char *s1, const char *s2, size_t n) 2805436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 2905436638acc7c010349a69c3395f1a57c642dc62Ying Wang register const unsigned char *p1 = (const unsigned char *) s1; 3005436638acc7c010349a69c3395f1a57c642dc62Ying Wang register const unsigned char *p2 = (const unsigned char *) s2; 3105436638acc7c010349a69c3395f1a57c642dc62Ying Wang unsigned char c1, c2; 3205436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3305436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (p1 == p2 || n == 0) 3405436638acc7c010349a69c3395f1a57c642dc62Ying Wang return 0; 3505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3605436638acc7c010349a69c3395f1a57c642dc62Ying Wang do 3705436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 3805436638acc7c010349a69c3395f1a57c642dc62Ying Wang c1 = c_tolower (*p1); 3905436638acc7c010349a69c3395f1a57c642dc62Ying Wang c2 = c_tolower (*p2); 4005436638acc7c010349a69c3395f1a57c642dc62Ying Wang 4105436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (--n == 0 || c1 == '\0') 4205436638acc7c010349a69c3395f1a57c642dc62Ying Wang break; 4305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 4405436638acc7c010349a69c3395f1a57c642dc62Ying Wang ++p1; 4505436638acc7c010349a69c3395f1a57c642dc62Ying Wang ++p2; 4605436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 4705436638acc7c010349a69c3395f1a57c642dc62Ying Wang while (c1 == c2); 4805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 4905436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (UCHAR_MAX <= INT_MAX) 5005436638acc7c010349a69c3395f1a57c642dc62Ying Wang return c1 - c2; 5105436638acc7c010349a69c3395f1a57c642dc62Ying Wang else 5205436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* On machines where 'char' and 'int' are types of the same size, the 5305436638acc7c010349a69c3395f1a57c642dc62Ying Wang difference of two 'unsigned char' values - including the sign bit - 5405436638acc7c010349a69c3395f1a57c642dc62Ying Wang doesn't fit in an 'int'. */ 5505436638acc7c010349a69c3395f1a57c642dc62Ying Wang return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0); 5605436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 57