xref: /minix/common/lib/libc/string/strchr.c (revision ebfedea0)
1 /*	$NetBSD: strchr.c,v 1.5 2011/08/31 15:48:32 plunky Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)index.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: strchr.c,v 1.5 2011/08/31 15:48:32 plunky Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #if !defined(_KERNEL) && !defined(_STANDALONE)
42 #include "namespace.h"
43 #include <assert.h>
44 #include <string.h>
45 #else
46 #include <lib/libkern/libkern.h>
47 #endif
48 
49 __strong_alias(index, strchr)
50 char *
51 strchr(const char *p, int ch)
52 {
53 	const char cmp = ch;
54 	_DIAGASSERT(p != NULL);
55 
56 	for (;; ++p) {
57 		if (*p == cmp) {
58 			/* LINTED const cast-away */
59 			return(__UNCONST(p));
60 		}
61 		if (!*p)
62 			return(NULL);
63 	}
64 	/* NOTREACHED */
65 }
66