xref: /dragonfly/lib/libc/string/index.c (revision ed36d35d)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)index.c	8.1 (Berkeley) 6/4/93
30  * $FreeBSD: src/lib/libc/string/index.c,v 1.8 2007/01/09 00:28:12 imp Exp $
31  * $DragonFly: src/lib/libc/string/index.c,v 1.4 2005/09/18 16:32:34 asmodai Exp $
32  */
33 
34 #include <stddef.h>
35 
36 #ifdef STRCHR
37 #include <string.h>
38 
39 char *
40 strchr
41 #else
42 #include <strings.h>
43 
44 char *
45 index
46 #endif
47 (const char *p, int ch)
48 {
49 	char c;
50 
51 	c = ch;
52 	for (;; ++p) {
53 		if (*p == c)
54 			return ((char *)p);
55 		if (*p == '\0')
56 			return (NULL);
57 	}
58 	/* NOTREACHED */
59 }
60