xref: /freebsd/lib/libc/string/strtok.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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 <stddef.h>
41 #ifdef DEBUG_STRTOK
42 #include <stdio.h>
43 #endif
44 #include <string.h>
45 
46 char	*__strtok_r(char *, const char *, char **);
47 
48 __weak_reference(__strtok_r, strtok_r);
49 
50 char *
51 __strtok_r(char *s, const char *delim, char **last)
52 {
53 	char *spanp, *tok;
54 	int c, sc;
55 
56 	if (s == NULL && (s = *last) == NULL)
57 		return (NULL);
58 
59 	/*
60 	 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
61 	 */
62 cont:
63 	c = *s++;
64 	for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
65 		if (c == sc)
66 			goto cont;
67 	}
68 
69 	if (c == 0) {		/* no non-delimiter characters */
70 		*last = NULL;
71 		return (NULL);
72 	}
73 	tok = s - 1;
74 
75 	/*
76 	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
77 	 * Note that delim must have one NUL; we stop if we see that, too.
78 	 */
79 	for (;;) {
80 		c = *s++;
81 		spanp = (char *)delim;
82 		do {
83 			if ((sc = *spanp++) == c) {
84 				if (c == 0)
85 					s = NULL;
86 				else
87 					s[-1] = '\0';
88 				*last = s;
89 				return (tok);
90 			}
91 		} while (sc != 0);
92 	}
93 	/* NOTREACHED */
94 }
95 
96 char *
97 strtok(char *s, const char *delim)
98 {
99 	static char *last;
100 
101 	return (__strtok_r(s, delim, &last));
102 }
103 
104 #ifdef DEBUG_STRTOK
105 /*
106  * Test the tokenizer.
107  */
108 int
109 main(void)
110 {
111 	char blah[80], test[80];
112 	char *brkb, *brkt, *phrase, *sep, *word;
113 
114 	sep = "\\/:;=-";
115 	phrase = "foo";
116 
117 	printf("String tokenizer test:\n");
118 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
119 	for (word = strtok(test, sep); word; word = strtok(NULL, sep))
120 		printf("Next word is \"%s\".\n", word);
121 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
122 
123 	for (word = strtok_r(test, sep, &brkt); word;
124 	    word = strtok_r(NULL, sep, &brkt)) {
125 		strcpy(blah, "blah:blat:blab:blag");
126 
127 		for (phrase = strtok_r(blah, sep, &brkb); phrase;
128 		    phrase = strtok_r(NULL, sep, &brkb))
129 			printf("So far we're at %s:%s\n", word, phrase);
130 	}
131 
132 	return (0);
133 }
134 
135 #endif /* DEBUG_STRTOK */
136