lib/ip/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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/types.h>
  35 #include <ansi.h>
  36 #include <strings.h>
  37 #include <ctype.h>
  38
  39 int
  40 strcasecmp(s1, s2)
  41         const char *s1, *s2;
  42 {
  43         const u_char
  44                         *us1 = (const u_char *)s1,
  45                         *us2 = (const u_char *)s2;
  46
  47         while (tolower(*us1) == tolower(*us2++))
  48                 if (*us1++ == '\0')
  49                         return (0);
  50         return (tolower(*us1) - tolower(*--us2));
  51 }
  52
  53 int
  54 strncasecmp(s1, s2, n)
  55         const char *s1, *s2;
  56         size_t n;
  57 {
  58         if (n != 0) {
  59                 const u_char
  60                                 *us1 = (const u_char *)s1,
  61                                 *us2 = (const u_char *)s2;
  62
  63                 do {
  64                         if (tolower(*us1) != tolower(*us2++))
  65                                 return (tolower(*us1) - tolower(*--us2));
  66                         if (*us1++ == '\0')
  67                                 break;
  68                 } while (--n != 0);
  69         }
  70         return (0);
  71 }