1*d2ea5f1aSchristos /* $NetBSD: strnstr.c,v 1.1 2014/09/24 22:21:33 christos Exp $ */
2*d2ea5f1aSchristos
3*d2ea5f1aSchristos /*-
4*d2ea5f1aSchristos * Copyright (c) 2001 Mike Barcroft <mike@FreeBSD.org>
5*d2ea5f1aSchristos * Copyright (c) 1990, 1993
6*d2ea5f1aSchristos * The Regents of the University of California. All rights reserved.
7*d2ea5f1aSchristos *
8*d2ea5f1aSchristos * This code is derived from software contributed to Berkeley by
9*d2ea5f1aSchristos * Chris Torek.
10*d2ea5f1aSchristos *
11*d2ea5f1aSchristos * Redistribution and use in source and binary forms, with or without
12*d2ea5f1aSchristos * modification, are permitted provided that the following conditions
13*d2ea5f1aSchristos * are met:
14*d2ea5f1aSchristos * 1. Redistributions of source code must retain the above copyright
15*d2ea5f1aSchristos * notice, this list of conditions and the following disclaimer.
16*d2ea5f1aSchristos * 2. Redistributions in binary form must reproduce the above copyright
17*d2ea5f1aSchristos * notice, this list of conditions and the following disclaimer in the
18*d2ea5f1aSchristos * documentation and/or other materials provided with the distribution.
19*d2ea5f1aSchristos * 3. Neither the name of the University nor the names of its contributors
20*d2ea5f1aSchristos * may be used to endorse or promote products derived from this software
21*d2ea5f1aSchristos * without specific prior written permission.
22*d2ea5f1aSchristos *
23*d2ea5f1aSchristos * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24*d2ea5f1aSchristos * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25*d2ea5f1aSchristos * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26*d2ea5f1aSchristos * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27*d2ea5f1aSchristos * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28*d2ea5f1aSchristos * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29*d2ea5f1aSchristos * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30*d2ea5f1aSchristos * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31*d2ea5f1aSchristos * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32*d2ea5f1aSchristos * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33*d2ea5f1aSchristos * SUCH DAMAGE.
34*d2ea5f1aSchristos */
35*d2ea5f1aSchristos
36*d2ea5f1aSchristos #include <sys/cdefs.h>
37*d2ea5f1aSchristos #if defined(LIBC_SCCS) && !defined(lint)
38*d2ea5f1aSchristos #if 0
39*d2ea5f1aSchristos static char sccsid[] = "@(#)strstr.c 8.1 (Berkeley) 6/4/93";
40*d2ea5f1aSchristos #else
41*d2ea5f1aSchristos __RCSID("$NetBSD: strnstr.c,v 1.1 2014/09/24 22:21:33 christos Exp $");
42*d2ea5f1aSchristos #endif
43*d2ea5f1aSchristos #endif /* LIBC_SCCS and not lint */
44*d2ea5f1aSchristos /* FreeBSD: head/lib/libc/string/strnstr.c 251069 2013-05-28 20:57:40Z emaste */
45*d2ea5f1aSchristos
46*d2ea5f1aSchristos #include <string.h>
47*d2ea5f1aSchristos
48*d2ea5f1aSchristos /*
49*d2ea5f1aSchristos * Find the first occurrence of find in s, where the search is limited to the
50*d2ea5f1aSchristos * first slen characters of s.
51*d2ea5f1aSchristos */
52*d2ea5f1aSchristos char *
strnstr(const char * s,const char * find,size_t slen)53*d2ea5f1aSchristos strnstr(const char *s, const char *find, size_t slen)
54*d2ea5f1aSchristos {
55*d2ea5f1aSchristos char c, sc;
56*d2ea5f1aSchristos size_t len;
57*d2ea5f1aSchristos
58*d2ea5f1aSchristos if ((c = *find++) != '\0') {
59*d2ea5f1aSchristos len = strlen(find);
60*d2ea5f1aSchristos do {
61*d2ea5f1aSchristos do {
62*d2ea5f1aSchristos if (slen-- < 1 || (sc = *s++) == '\0')
63*d2ea5f1aSchristos return NULL;
64*d2ea5f1aSchristos } while (sc != c);
65*d2ea5f1aSchristos if (len > slen)
66*d2ea5f1aSchristos return NULL;
67*d2ea5f1aSchristos } while (strncmp(s, find, len) != 0);
68*d2ea5f1aSchristos s--;
69*d2ea5f1aSchristos }
70*d2ea5f1aSchristos return __UNCONST(s);
71*d2ea5f1aSchristos }
72