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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
25 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOFTWEYR LLC, THE
26 * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
28 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #define _POSIX_SOURCE 1
36 #include <string.h>
37
38 /*
39 * strtok_r documentation:
40 * http://pubs.opengroup.org/onlinepubs/009695399/functions/strtok.html
41 *
42 * Implementation:
43 * http://svnweb.freebsd.org/base/head/lib/libc/string/strtok.c?view=co
44 *
45 * strtok_r cannot completely be implemented by strtok because of the internal state.
46 * It breaks when used on 2 strings where they are scanned A, B then A, B.
47 * Thread-safety is not the issue.
48 *
49 * Sample strtok implemenatation, note the internal state:
50 * char *strtok(char *s, const char *d) { static char *t; return strtok_r(s,d,t); }
51 *
52 */
53
54 char *
strtok_r(char * __restrict s,const char * __restrict delim,char ** __restrict last)55 strtok_r(char * __restrict s, const char * __restrict delim, char ** __restrict last)
56 {
57 char *spanp, *tok;
58 int c, sc;
59
60 if (s == NULL && (s = *last) == NULL)
61 return (NULL);
62
63 /*
64 * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
65 */
66 cont:
67 c = *s++;
68 for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
69 if (c == sc)
70 goto cont;
71 }
72
73 if (c == 0) { /* no non-delimiter characters */
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 c = *s++;
85 spanp = (char *)delim;
86 do {
87 if ((sc = *spanp++) == c) {
88 if (c == 0)
89 s = NULL;
90 else
91 s[-1] = '\0';
92 *last = s;
93 return (tok);
94 }
95 } while (sc != 0);
96 }
97 /* NOTREACHED */
98 }
99