lib/libstand/strcasecmp.c

   1 /*
   2  * Copyright (c) 1987, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)strcasecmp.c     8.1 (Berkeley) 6/4/93
  30  */
  31
  32 #include <string.h>
  33 #include "stand.h"
  34
  35 int
  36 strcasecmp(const char *s1, const char *s2)
  37 {
  38         const u_char
  39                         *us1 = (const u_char *)s1,
  40                         *us2 = (const u_char *)s2;
  41
  42         while (tolower(*us1) == tolower(*us2++))
  43                 if (*us1++ == '\0')
  44                         return (0);
  45         return (tolower(*us1) - tolower(*--us2));
  46 }
  47
  48 int
  49 strncasecmp(const char *s1, const char *s2, size_t n)
  50 {
  51         if (n != 0) {
  52                 const u_char
  53                                 *us1 = (const u_char *)s1,
  54                                 *us2 = (const u_char *)s2;
  55
  56                 do {
  57                         if (tolower(*us1) != tolower(*us2++))
  58                                 return (tolower(*us1) - tolower(*--us2));
  59                         if (*us1++ == '\0')
  60                                 break;
  61                 } while (--n != 0);
  62         }
  63         return (0);
  64 }