xref: /freebsd/lib/libc/string/strtok.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
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 #ifndef lint
45 static const char rcsid[] =
46   "$FreeBSD$";
47 #endif
48 
49 #include <stddef.h>
50 #include <string.h>
51 
52 char *
53 strtok_r(char *s, const char *delim, char **last)
54 {
55     char *spanp;
56     int c, sc;
57     char *tok;
58 
59     if (s == NULL && (s = *last) == NULL)
60     {
61 	return NULL;
62     }
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     {
71 	if (c == sc)
72 	{
73 	    goto cont;
74 	}
75     }
76 
77     if (c == 0)		/* no non-delimiter characters */
78     {
79 	*last = NULL;
80 	return NULL;
81     }
82     tok = s - 1;
83 
84     /*
85      * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
86      * Note that delim must have one NUL; we stop if we see that, too.
87      */
88     for (;;)
89     {
90 	c = *s++;
91 	spanp = (char *)delim;
92 	do
93 	{
94 	    if ((sc = *spanp++) == c)
95 	    {
96 		if (c == 0)
97 		{
98 		    s = NULL;
99 		}
100 		else
101 		{
102 		    char *w = s - 1;
103 		    *w = '\0';
104 		}
105 		*last = s;
106 		return tok;
107 	    }
108 	}
109 	while (sc != 0);
110     }
111     /* NOTREACHED */
112 }
113 
114 
115 char *
116 strtok(char *s, const char *delim)
117 {
118     static char *last;
119 
120     return strtok_r(s, delim, &last);
121 }
122 
123 
124 #if defined(DEBUG_STRTOK)
125 
126 /*
127  * Test the tokenizer.
128  */
129 int
130 main()
131 {
132     char test[80], blah[80];
133     char *sep = "\\/:;=-";
134     char *word, *phrase, *brkt, *brkb;
135 
136     printf("String tokenizer test:\n");
137 
138     strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
139 
140     for (word = strtok(test, sep);
141 	 word;
142 	 word = strtok(NULL, sep))
143     {
144 	printf("Next word is \"%s\".\n", word);
145     }
146 
147     phrase = "foo";
148 
149     strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
150 
151     for (word = strtok_r(test, sep, &brkt);
152 	 word;
153 	 word = strtok_r(NULL, sep, &brkt))
154     {
155 	strcpy(blah, "blah:blat:blab:blag");
156 
157 	for (phrase = strtok_r(blah, sep, &brkb);
158 	     phrase;
159 	     phrase = strtok_r(NULL, sep, &brkb))
160 	{
161 	    printf("So far we're at %s:%s\n", word, phrase);
162 	}
163     }
164 
165     return 0;
166 }
167 
168 #endif /* DEBUG_STRTOK */
169