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/*-
* Copyright (c) 2001 Andrew L. Neporada <andr@dgap.mipt.ru>
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "bbs.h"
#ifndef SOLARIS
#include <sys/cdefs.h>
#endif
#include <sys/types.h>
#include <limits.h>
#include <string.h>
#ifndef HAVE_MEMMEM
/*
* Find the first occurrence of byte string p in byte string s.
*
* This implementation uses simplified Boyer-Moore algorithm (only
* bad-character shift table is used).
* See:
* Boyer R.S., Moore J.S. 1977, "A fast string searching algorithm",
* Communications of ACM. 20:762-772.
*/
void *totem_private_memmem(s, slen, p, plen)
register const void *s, *p;
size_t slen, plen;
{
register const u_char *str, *substr;
register size_t i, max_shift, curr_shift;
size_t shift[UCHAR_MAX + 1];
if (!plen)
return ((void *) s);
if (plen > slen)
return (NULL);
str = (const u_char *) s;
substr = (const u_char *) p;
for (i = 0; i <= UCHAR_MAX; i++)
shift[i] = plen + 1;
for (i = 0; i < plen; i++)
shift[substr[i]] = plen - i;
i = 0;
max_shift = slen - plen;
while (i <= max_shift) {
if (*str == *substr && !memcmp(str + 1, substr + 1, plen - 1))
return ((void *) str);
curr_shift = shift[str[plen]];
str += curr_shift;
i += curr_shift;
}
return (NULL);
}
#endif /* ! HAVE_MEMMEM */
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