xref: /netbsd-src/lib/libc/string/strtok_r.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*
2  * Copyright (c) 1988 Regents of the University of California.
3  * 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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 /*static char *sccsid = "from: @(#)strtok.c	5.8 (Berkeley) 2/24/91";*/
36 static char *rcsid = "$Id: strtok_r.c,v 1.1 1996/11/12 02:03:14 jtc Exp $";
37 #endif /* LIBC_SCCS and not lint */
38 
39 #include <string.h>
40 
41 char *
42 strtok_r(s, delim, lasts)
43 	register char *s;
44 	register const char *delim;
45 	register char **lasts;
46 {
47 	register char *spanp;
48 	register int c, sc;
49 	char *tok;
50 
51 	if (s == NULL && (s = *lasts) == NULL)
52 		return (NULL);
53 
54 	/*
55 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
56 	 */
57 cont:
58 	c = *s++;
59 	for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
60 		if (c == sc)
61 			goto cont;
62 	}
63 
64 	if (c == 0) {		/* no non-delimiter characters */
65 		*lasts = NULL;
66 		return (NULL);
67 	}
68 	tok = s - 1;
69 
70 	/*
71 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
72 	 * Note that delim must have one NUL; we stop if we see that, too.
73 	 */
74 	for (;;) {
75 		c = *s++;
76 		spanp = (char *)delim;
77 		do {
78 			if ((sc = *spanp++) == c) {
79 				if (c == 0)
80 					s = NULL;
81 				else
82 					s[-1] = 0;
83 				*lasts = s;
84 				return (tok);
85 			}
86 		} while (sc != 0);
87 	}
88 	/* NOTREACHED */
89 }
90