xref: /freebsd/lib/libc/string/strtok.c (revision 3047fefe49f57a673de8df152c199de12ec2c6d3)
1 /*-
2  * Copyright (c) 1998 Softweyr LLC.  All rights reserved.
3  *
4  * strtok_r, from Berkeley strtok
5  * Oct 13, 1998 by Wes Peters <wes@softweyr.com>
6  *
7  * Copyright (c) 1988, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notices, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notices, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by Softweyr LLC, the
21  *      University of California, Berkeley, and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE
30  * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
31  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
32  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #if defined(LIBC_SCCS) && !defined(lint)
40 static char sccsid[] = "@(#)strtok.c	8.1 (Berkeley) 6/4/93";
41 #endif /* LIBC_SCCS and not lint */
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <stddef.h>
46 #ifdef DEBUG_STRTOK
47 #include <stdio.h>
48 #endif
49 #include <string.h>
50 
51 char	*__strtok_r(char *, const char *, char **);
52 
53 __weak_reference(__strtok_r, strtok_r);
54 
55 char *
56 __strtok_r(char *s, const char *delim, char **last)
57 {
58 	char *spanp, *tok;
59 	int c, sc;
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 	 */
67 cont:
68 	c = *s++;
69 	for (spanp = (char *)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 = (char *)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 
101 char *
102 strtok(char *s, const char *delim)
103 {
104 	static char *last;
105 
106 	return (__strtok_r(s, delim, &last));
107 }
108 
109 #ifdef DEBUG_STRTOK
110 /*
111  * Test the tokenizer.
112  */
113 int
114 main(void)
115 {
116 	char blah[80], test[80];
117 	char *brkb, *brkt, *phrase, *sep, *word;
118 
119 	sep = "\\/:;=-";
120 	phrase = "foo";
121 
122 	printf("String tokenizer test:\n");
123 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
124 	for (word = strtok(test, sep); word; word = strtok(NULL, sep))
125 		printf("Next word is \"%s\".\n", word);
126 	strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
127 
128 	for (word = strtok_r(test, sep, &brkt); word;
129 	    word = strtok_r(NULL, sep, &brkt)) {
130 		strcpy(blah, "blah:blat:blab:blag");
131 
132 		for (phrase = strtok_r(blah, sep, &brkb); phrase;
133 		    phrase = strtok_r(NULL, sep, &brkb))
134 			printf("So far we're at %s:%s\n", word, phrase);
135 	}
136 
137 	return (0);
138 }
139 
140 #endif /* DEBUG_STRTOK */
141