lib/libc/string/memrchr.c

   1 /*      $OpenBSD: memrchr.c,v 1.2 2007/11/27 16:22:12 martynas Exp $    */
   2
   3 /*
   4  * Copyright (c) 2007 Todd C. Miller <Todd.Miller@courtesan.com>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  * $FreeBSD: head/lib/libc/string/memrchr.c 178051 2008-04-10 00:12:44Z delphij $
  19  */
  20
  21 #include <string.h>
  22
  23 /*
  24  * Reverse memchr()
  25  * Find the last occurrence of 'c' in the buffer 's' of size 'n'.
  26  */
  27 void *
  28 memrchr(const void *s, int c, size_t n)
  29 {
  30         const unsigned char *cp;
  31
  32         if (n != 0) {
  33                 cp = (unsigned char *)s + n;
  34                 do {
  35                         if (*(--cp) == (unsigned char)c)
  36                                 return((void *)cp);
  37                 } while (--n != 0);
  38         }
  39         return(NULL);
  40 }