freebsd-dev/lib/libc/string/memrchr.c
Xin LI 82e45205c8 Add memrchr(3).
Obtained from:	OpenBSD
2008-04-10 00:12:44 +00:00

41 lines
1.2 KiB
C

/* $OpenBSD: memrchr.c,v 1.2 2007/11/27 16:22:12 martynas Exp $ */
/*
* Copyright (c) 2007 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* $FreeBSD$
*/
#include <string.h>
/*
* Reverse memchr()
* Find the last occurrence of 'c' in the buffer 's' of size 'n'.
*/
void *
memrchr(const void *s, int c, size_t n)
{
const unsigned char *cp;
if (n != 0) {
cp = (unsigned char *)s + n;
do {
if (*(--cp) == (unsigned char)c)
return((void *)cp);
} while (--n != 0);
}
return(NULL);
}