freebsd-dev/lib/libc/string/wcsstr.c
Tim J. Robbins fcd7f38f46 Replace wcsstr() with an implementation based on strstr(), which is far
more efficient. The problem with the previous implementation was that it
calculated the length of the first argument ("big") with wcslen() when
it was not necessary.
2002-10-24 02:53:45 +00:00

68 lines
2.5 KiB
C

/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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.
*/
#if 0
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strstr.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <wchar.h>
/*
* Find the first occurrence of find in s.
*/
wchar_t *
wcsstr(const wchar_t * __restrict s, const wchar_t * __restrict find)
{
wchar_t c, sc;
size_t len;
if ((c = *find++) != 0) {
len = wcslen(find);
do {
do {
if ((sc = *s++) == L'\0')
return (NULL);
} while (sc != c);
} while (wcsncmp(s, find, len) != 0);
s--;
}
return ((wchar_t *)s);
}