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      1 /*	$OpenBSD: memrchr.c,v 1.3 2015/08/31 02:53:57 guenther Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2007 Todd C. Miller <Todd.Miller (at) 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 
     19 #include <string.h>
     20 
     21 /*
     22  * Reverse memchr()
     23  * Find the last occurrence of 'c' in the buffer 's' of size 'n'.
     24  */
     25 void *
     26 memrchr(const void *s, int c, size_t n)
     27 {
     28 	const unsigned char *cp;
     29 
     30 	if (n != 0) {
     31 		cp = (unsigned char *)s + n;
     32 		do {
     33 			if (*(--cp) == (unsigned char)c)
     34 				return((void *)cp);
     35 		} while (--n != 0);
     36 	}
     37 	return(NULL);
     38 }
     39 DEF_WEAK(memrchr);
     40