strtok.c revision 1.10 
1/*	$NetBSD: strtok.c,v 1.10 1999/09/20 04:39:49 lukem 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 1.10 1999/09/20 04:39:49 lukem Exp $");
42#endif
43#endif /* LIBC_SCCS and not lint */
44
45#include <assert.h>
46#include <string.h>
47
48char *
49strtok(s, delim)
50	char *s;
51	const char *delim;
52{
53	const char *spanp;
54	int c, sc;
55	char *tok;
56	static char *last;
57
58	/* s may be NULL */
59	_DIAGASSERT(delim != NULL);
60
61	if (s == NULL && (s = last) == NULL)
62		return (NULL);
63
64	/*
65	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
66	 */
67cont:
68	c = *s++;
69	for (spanp = delim; (sc = *spanp++) != 0;) {
70		if (c == sc)
71			goto cont;
72	}
73
74	if (c == 0) {		/* no non-delimiter characters */
75		last = NULL;
76		return (NULL);
77	}
78	tok = s - 1;
79
80	/*
81	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
82	 * Note that delim must have one NUL; we stop if we see that, too.
83	 */
84	for (;;) {
85		c = *s++;
86		spanp = delim;
87		do {
88			if ((sc = *spanp++) == c) {
89				if (c == 0)
90					s = NULL;
91				else
92					s[-1] = 0;
93				last = s;
94				return (tok);
95			}
96		} while (sc != 0);
97	}
98	/* NOTREACHED */
99}
100