xref: /freebsd/lib/libc/string/wcstok.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <sys/cdefs.h>
38 #include <wchar.h>
39 
40 wchar_t *
41 wcstok(wchar_t * __restrict s, const wchar_t * __restrict delim,
42     wchar_t ** __restrict last)
43 {
44 	const wchar_t *spanp;
45 	wchar_t *tok;
46 	wchar_t c, sc;
47 
48 	if (s == NULL && (s = *last) == NULL)
49 		return (NULL);
50 
51 	/*
52 	 * Skip (span) leading delimiters (s += wcsspn(s, delim), sort of).
53 	 */
54 cont:
55 	c = *s++;
56 	for (spanp = delim; (sc = *spanp++) != L'\0';) {
57 		if (c == sc)
58 			goto cont;
59 	}
60 
61 	if (c == L'\0') {	/* no non-delimiter characters */
62 		*last = NULL;
63 		return (NULL);
64 	}
65 	tok = s - 1;
66 
67 	/*
68 	 * Scan token (scan for delimiters: s += wcscspn(s, delim), sort of).
69 	 * Note that delim must have one NUL; we stop if we see that, too.
70 	 */
71 	for (;;) {
72 		c = *s++;
73 		spanp = delim;
74 		do {
75 			if ((sc = *spanp++) == c) {
76 				if (c == L'\0')
77 					s = NULL;
78 				else
79 					s[-1] = L'\0';
80 				*last = s;
81 				return (tok);
82 			}
83 		} while (sc != L'\0');
84 	}
85 	/* NOTREACHED */
86 }
87