strtok.c revision 1.7 
1/*	$NetBSD: strtok.c,v 1.7 1998/02/03 18:49:25 perry Exp $	*/
2
3/*
4 * Copyright (c) 1988, 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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37#if defined(LIBC_SCCS) && !defined(lint)
38#if 0
39static char sccsid[] = "@(#)strtok.c	8.1 (Berkeley) 6/4/93";
40#else
41__RCSID("$NetBSD: strtok.c,v 1.7 1998/02/03 18:49:25 perry Exp $");
42#endif
43#endif /* LIBC_SCCS and not lint */
44
45#include <string.h>
46
47char *
48strtok(s, delim)
49	char *s;
50	const char *delim;
51{
52	char *spanp;
53	int c, sc;
54	char *tok;
55	static char *last;
56
57
58	if (s == NULL && (s = last) == NULL)
59		return (NULL);
60
61	/*
62	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
63	 */
64cont:
65	c = *s++;
66	for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
67		if (c == sc)
68			goto cont;
69	}
70
71	if (c == 0) {		/* no non-delimiter characters */
72		last = NULL;
73		return (NULL);
74	}
75	tok = s - 1;
76
77	/*
78	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
79	 * Note that delim must have one NUL; we stop if we see that, too.
80	 */
81	for (;;) {
82		c = *s++;
83		spanp = (char *)delim;
84		do {
85			if ((sc = *spanp++) == c) {
86				if (c == 0)
87					s = NULL;
88				else
89					s[-1] = 0;
90				last = s;
91				return (tok);
92			}
93		} while (sc != 0);
94	}
95	/* NOTREACHED */
96}
97