xref: /freebsd/lib/libc/string/strtok.c (revision b1e12513fa34f8ef59f4217dc502a739ecba0c44)
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  *
14  * 1. Redistributions of source code must retain the above copyright
15  *    notices, this list of conditions and the following disclaimer.
16  *
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  *
21  * 3. All advertising materials mentioning features or use of this software
22  *    must display the following acknowledgement:
23  *
24  *	This product includes software developed by Softweyr LLC, the
25  *      University of California, Berkeley, and its contributors.
26  *
27  * 4. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
32  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
34  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE
35  * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
37  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
38  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
39  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
40  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
41  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42  */
43 
44 #include <stddef.h>
45 #include <string.h>
46 
47 char *
48 strtok_r(char *s, const char *delim, char **last)
49 {
50     char *spanp;
51     int c, sc;
52     char *tok;
53 
54     if (s == NULL && (s = *last) == NULL)
55     {
56 	return NULL;
57     }
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     {
66 	if (c == sc)
67 	{
68 	    goto cont;
69 	}
70     }
71 
72     if (c == 0)		/* no non-delimiter characters */
73     {
74 	*last = NULL;
75 	return NULL;
76     }
77     tok = s - 1;
78 
79     /*
80      * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
81      * Note that delim must have one NUL; we stop if we see that, too.
82      */
83     for (;;)
84     {
85 	c = *s++;
86 	spanp = (char *)delim;
87 	do
88 	{
89 	    if ((sc = *spanp++) == c)
90 	    {
91 		if (c == 0)
92 		{
93 		    s = NULL;
94 		}
95 		else
96 		{
97 		    char *w = s - 1;
98 		    *w = '\0';
99 		}
100 		*last = s;
101 		return tok;
102 	    }
103 	}
104 	while (sc != 0);
105     }
106     /* NOTREACHED */
107 }
108 
109 
110 char *
111 strtok(char *s, const char *delim)
112 {
113     static char *last;
114 
115     return strtok_r(s, delim, &last);
116 }
117 
118 
119 #if defined(DEBUG_STRTOK)
120 
121 /*
122  * Test the tokenizer.
123  */
124 int
125 main()
126 {
127     char test[80], blah[80];
128     char *sep = "\\/:;=-";
129     char *word, *phrase, *brkt, *brkb;
130 
131     printf("String tokenizer test:\n");
132 
133     strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
134 
135     for (word = strtok(test, sep);
136 	 word;
137 	 word = strtok(NULL, sep))
138     {
139 	printf("Next word is \"%s\".\n", word);
140     }
141 
142     phrase = "foo";
143 
144     strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
145 
146     for (word = strtok_r(test, sep, &brkt);
147 	 word;
148 	 word = strtok_r(NULL, sep, &brkt))
149     {
150 	strcpy(blah, "blah:blat:blab:blag");
151 
152 	for (phrase = strtok_r(blah, sep, &brkb);
153 	     phrase;
154 	     phrase = strtok_r(NULL, sep, &brkb))
155 	{
156 	    printf("So far we're at %s:%s\n", word, phrase);
157 	}
158     }
159 
160     return 0;
161 }
162 
163 #endif /* DEBUG_STRTOK */
164