compat/memrchr.c

   1 /*
   2  * Copyright (c) 2007 Todd C. Miller <Todd.Miller@courtesan.com>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  *
  16  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include <string.h>
  23
  24 /*
  25  * Reverse memchr()
  26  * Find the last occurrence of 'c' in the buffer 's' of size 'n'.
  27  */
  28 void *
  29 memrchr(const void *s, int c, size_t n)
  30 {
  31     const unsigned char *cp;
  32
  33     if (n != 0) {
  34         cp = (unsigned char *)s + n;
  35         do {
  36             if (*(--cp) == (unsigned char)c)
  37                 return((void *)cp);
  38         } while (--n != 0);
  39     }
  40     return(NULL);
  41 }