xref: /freebsd/lib/libc/locale/mbstowcs.c (revision 58d38e25205c6ee5ef0796ffa2cd8e2ca6c6e7f3)
1 /*-
2  * Copyright (c) 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Paul Borman at Krystal Technologies.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. 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 THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <errno.h>
41 #include <stdlib.h>
42 #include <limits.h>
43 #include <stddef.h>
44 #include <rune.h>
45 
46 size_t
47 mbstowcs(pwcs, s, n)
48 	wchar_t * __restrict pwcs;
49 	const char * __restrict s;
50 	size_t n;
51 {
52 	char const *e;
53 	int cnt = 0;
54 	rune_t r;
55 
56 	if (!s) {
57 		errno = EINVAL;
58 		return (-1);
59 	}
60 
61 	if (pwcs == NULL) {
62 		/* Convert and count only, do not store. */
63 		while ((r = sgetrune(s, MB_LEN_MAX, &e)) != _INVALID_RUNE &&
64 		    r != 0) {
65 			s = e;
66 			cnt++;
67 		}
68 		if (r == _INVALID_RUNE) {
69 			errno = EILSEQ;
70 			return (-1);
71 		}
72 	}
73 
74 	/* Convert, store and count characters. */
75 	while (n-- > 0) {
76 		*pwcs = sgetrune(s, MB_LEN_MAX, &e);
77 		if (*pwcs == _INVALID_RUNE) {
78 			errno = EILSEQ;
79 			return (-1);
80 		}
81 		if (*pwcs++ == 0)
82 			break;
83 		s = e;
84 		++cnt;
85 	}
86 
87 	return (cnt);
88 }
89