xref: /freebsd/lib/libc/string/strtok.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <stddef.h>
42 #ifdef DEBUG_STRTOK
43 #include <stdio.h>
44 #endif
45 #include <string.h>
46 
47 char	*__strtok_r(char *, const char *, char **);
48 
49 __weak_reference(__strtok_r, strtok_r);
50 
51 char *
52 __strtok_r(char *s, const char *delim, char **last)
53 {
54 	char *spanp, *tok;
55 	int c, sc;
56 
57 	if (s == NULL && (s = *last) == NULL)
58 		return (NULL);
59 
60 	/*
61 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
62 	 */
63 cont:
64 	c = *s++;
65 	for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
66 		if (c == sc)
67 			goto cont;
68 	}
69 
70 	if (c == 0) {		/* no non-delimiter characters */
71 		*last = NULL;
72 		return (NULL);
73 	}
74 	tok = s - 1;
75 
76 	/*
77 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
78 	 * Note that delim must have one NUL; we stop if we see that, too.
79 	 */
80 	for (;;) {
81 		c = *s++;
82 		spanp = (char *)delim;
83 		do {
84 			if ((sc = *spanp++) == c) {
85 				if (c == 0)
86 					s = NULL;
87 				else
88 					s[-1] = '\0';
89 				*last = s;
90 				return (tok);
91 			}
92 		} while (sc != 0);
93 	}
94 	/* NOTREACHED */
95 }
96 
97 char *
98 strtok(char *s, const char *delim)
99 {
100 	static char *last;
101 
102 	return (__strtok_r(s, delim, &last));
103 }
104 
105 #ifdef DEBUG_STRTOK
106 /*
107  * Test the tokenizer.
108  */
109 int
110 main(void)
111 {
112 	char blah[80], test[80];
113 	char *brkb, *brkt, *phrase, *sep, *word;
114 
115 	sep = "\\/:;=-";
116 	phrase = "foo";
117 
118 	printf("String tokenizer test:\n");
119 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
120 	for (word = strtok(test, sep); word; word = strtok(NULL, sep))
121 		printf("Next word is \"%s\".\n", word);
122 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
123 
124 	for (word = strtok_r(test, sep, &brkt); word;
125 	    word = strtok_r(NULL, sep, &brkt)) {
126 		strcpy(blah, "blah:blat:blab:blag");
127 
128 		for (phrase = strtok_r(blah, sep, &brkb); phrase;
129 		    phrase = strtok_r(NULL, sep, &brkb))
130 			printf("So far we're at %s:%s\n", word, phrase);
131 	}
132 
133 	return (0);
134 }
135 
136 #endif /* DEBUG_STRTOK */
137