Line data    Source code

       1             : /*      $OpenBSD: strncasecmp.c,v 1.6 2014/06/10 04:16:57 deraadt Exp $ */
       2             : 
       3             : /*
       4             :  * Copyright (c) 1994 Christian E. Hopps
       5             :  * All rights reserved.
       6             :  *
       7             :  * Redistribution and use in source and binary forms, with or without
       8             :  * modification, are permitted provided that the following conditions
       9             :  * are met:
      10             :  * 1. Redistributions of source code must retain the above copyright
      11             :  *    notice, this list of conditions and the following disclaimer.
      12             :  * 2. Redistributions in binary form must reproduce the above copyright
      13             :  *    notice, this list of conditions and the following disclaimer in the
      14             :  *    documentation and/or other materials provided with the distribution.
      15             :  * 3. All advertising materials mentioning features or use of this software
      16             :  *    must display the following acknowledgement:
      17             :  *      This product includes software developed by Christian E. Hopps.
      18             :  * 4. The name of the author may not be used to endorse or promote products
      19             :  *    derived from this software without specific prior written permission
      20             :  *
      21             :  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
      22             :  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
      23             :  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
      24             :  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
      25             :  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
      26             :  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      27             :  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      28             :  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      29             :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
      30             :  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      31             :  */
      32             : 
      33             : #include <lib/libkern/libkern.h>
      34             : 
      35             : int
      36           0 : strncasecmp(const char *s1, const char *s2, size_t n)
      37             : {
      38           0 :         if (n == 0)
      39           0 :                 return 0;
      40             : 
      41           0 :         do {
      42           0 :                 unsigned char c1 = (unsigned char) *s1++;
      43           0 :                 unsigned char c2 = (unsigned char) *s2++;
      44             : 
      45           0 :                 if (c1 != c2) {
      46           0 :                         if (c1 >= 'A' && c1 <= 'Z' && 
      47           0 :                             c2 >= 'a' && c2 <= 'z')
      48           0 :                                 c1 += 'a' - 'A';
      49           0 :                         else if (c1 >= 'a' && c1 <= 'z' && 
      50           0 :                                  c2 >= 'A' && c2 <= 'Z')
      51           0 :                                 c2 += 'a' - 'A';
      52           0 :                         if (c1 != c2)
      53           0 :                                 return c1 - c2;
      54             :                 }
      55           0 :                 if (c1 == 0)
      56           0 :                         break;
      57           0 :         } while (--n != 0);
      58             : 
      59           0 :         return 0;
      60           0 : }