StdLib/LibC/String/strncasecmp.c

   1 /** @file
   2   strncasecmp implementation
   3
   4   Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials are licensed and made available under
   6   the terms and conditions of the BSD License that accompanies this distribution.
   7   The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13  * Copyright (c) 1987, 1993
  14  *  The Regents of the University of California.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  * 3. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39
  40   $NetBSD: strncasecmp.c,v 1.2 2007/06/04 18:19:27 christos Exp $
  41   strcasecmp.c  8.1 (Berkeley) 6/4/93
  42 **/
  43 #include <LibConfig.h>
  44 #include <sys/cdefs.h>
  45
  46 #if !defined(_KERNEL) && !defined(_STANDALONE)
  47 #include "namespace.h"
  48 #include <assert.h>
  49 #include <ctype.h>
  50 #include <string.h>
  51 #ifdef __weak_alias
  52 __weak_alias(strcasecmp,_strcasecmp)
  53 __weak_alias(strncasecmp,_strncasecmp)
  54 #endif
  55 #else
  56 #include <lib/libkern/libkern.h>
  57 #include <machine/limits.h>
  58 #endif
  59
  60 int
  61 strncasecmp(const char *s1, const char *s2, size_t n)
  62 {
  63   int   CompareVal;
  64
  65   _DIAGASSERT(s1 != NULL);
  66   _DIAGASSERT(s2 != NULL);
  67
  68   if (n != 0) {
  69     do {
  70       CompareVal = tolower(*s1) - tolower(*s2);
  71       if (CompareVal != 0) {
  72         return (CompareVal);
  73       }
  74       ++s1;
  75       ++s2;
  76       if (*s1 == '\0') {
  77         break;
  78       }
  79     } while (--n != 0);
  80   }
  81   return (0);
  82 }