xref: /freebsd/lib/libc/string/strtok.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1998 Softweyr LLC.  All rights reserved.
5  *
6  * strtok_r, from Berkeley strtok
7  * Oct 13, 1998 by Wes Peters <wes@softweyr.com>
8  *
9  * Copyright (c) 1988, 1993
10  *	The Regents of the University of California.  All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notices, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notices, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
25  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
27  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE
28  * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
30  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid[] = "@(#)strtok.c	8.1 (Berkeley) 6/4/93";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <stddef.h>
44 #ifdef DEBUG_STRTOK
45 #include <stdio.h>
46 #endif
47 #include <string.h>
48 
49 char	*__strtok_r(char *, const char *, char **);
50 
51 __weak_reference(__strtok_r, strtok_r);
52 
53 char *
54 __strtok_r(char *s, const char *delim, char **last)
55 {
56 	char *spanp, *tok;
57 	int c, sc;
58 
59 	if (s == NULL && (s = *last) == NULL)
60 		return (NULL);
61 
62 	/*
63 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
64 	 */
65 cont:
66 	c = *s++;
67 	for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
68 		if (c == sc)
69 			goto cont;
70 	}
71 
72 	if (c == 0) {		/* no non-delimiter characters */
73 		*last = NULL;
74 		return (NULL);
75 	}
76 	tok = s - 1;
77 
78 	/*
79 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
80 	 * Note that delim must have one NUL; we stop if we see that, too.
81 	 */
82 	for (;;) {
83 		c = *s++;
84 		spanp = (char *)delim;
85 		do {
86 			if ((sc = *spanp++) == c) {
87 				if (c == 0)
88 					s = NULL;
89 				else
90 					s[-1] = '\0';
91 				*last = s;
92 				return (tok);
93 			}
94 		} while (sc != 0);
95 	}
96 	/* NOTREACHED */
97 }
98 
99 char *
100 strtok(char *s, const char *delim)
101 {
102 	static char *last;
103 
104 	return (__strtok_r(s, delim, &last));
105 }
106 
107 #ifdef DEBUG_STRTOK
108 /*
109  * Test the tokenizer.
110  */
111 int
112 main(void)
113 {
114 	char blah[80], test[80];
115 	char *brkb, *brkt, *phrase, *sep, *word;
116 
117 	sep = "\\/:;=-";
118 	phrase = "foo";
119 
120 	printf("String tokenizer test:\n");
121 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
122 	for (word = strtok(test, sep); word; word = strtok(NULL, sep))
123 		printf("Next word is \"%s\".\n", word);
124 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
125 
126 	for (word = strtok_r(test, sep, &brkt); word;
127 	    word = strtok_r(NULL, sep, &brkt)) {
128 		strcpy(blah, "blah:blat:blab:blag");
129 
130 		for (phrase = strtok_r(blah, sep, &brkb); phrase;
131 		    phrase = strtok_r(NULL, sep, &brkb))
132 			printf("So far we're at %s:%s\n", word, phrase);
133 	}
134 
135 	return (0);
136 }
137 
138 #endif /* DEBUG_STRTOK */
139