0 /*-

1 * Copyright (c) 2001 Mike Barcroft <mike@FreeBSD.org>

2 * Copyright (c) 1990, 1993

3 * The Regents of the University of California. All rights reserved.

4 *

5 * This code is derived from software contributed to Berkeley by

6 * Chris Torek.

7 *

8 * Redistribution and use in source and binary forms, with or without

9 * modification, are permitted provided that the following conditions

10 * are met:

11 * 1. Redistributions of source code must retain the above copyright

12 * notice, this list of conditions and the following disclaimer.

13 * 2. Redistributions in binary form must reproduce the above copyright

14 * notice, this list of conditions and the following disclaimer in the

15 * documentation and/or other materials provided with the distribution.

16 * 4. Neither the name of the University nor the names of its contributors

17 * may be used to endorse or promote products derived from this software

18 * without specific prior written permission.

19 *

20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

30 * SUCH DAMAGE.

31 */

32

33 #include <string.h>

34

35 /*

36 * Find the first occurrence of find in s, where the search is limited to the

37 * first slen characters of s.

38 */

39 char *

40 strnstr(const char *s, const char *find, size_t slen)

41 {

42 char c, sc;

43 size_t len;

44

45 if ((c = *find++) != '\0') {

46 len = strlen(find);

47 do {

48 do {

49 if (slen-- < 1 || (sc = *s++) == '\0')

50 return (NULL);

51 } while (sc != c);

52 if (len > slen)

53 return (NULL);

54 } while (strncmp(s, find, len) != 0);

55 s--;

56 }

57 return ((char *)s);

58 }

59