xref: /freebsd/lib/libc/locale/mbsrtowcs.c (revision c4f6a2a9e1b1879b618c436ab4f56ff75c73a0f5)
1 /*-
2  * Copyright (c) 2002 Tim J. Robbins.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <errno.h>
31 #include <limits.h>
32 #include <stdlib.h>
33 #include <wchar.h>
34 
35 size_t
36 mbsrtowcs(wchar_t *__restrict dst, const char **__restrict src, size_t len,
37     mbstate_t *__restrict ps __unused)
38 {
39 	const char *s;
40 	size_t nchr;
41 	wchar_t wc;
42 	int nb;
43 
44 	s = *src;
45 	nchr = 0;
46 
47 	if (dst == NULL) {
48 		for (;;) {
49 			if ((nb = (int)mbrtowc(&wc, s, MB_CUR_MAX, NULL)) < 0)
50 				/* Invalid sequence - mbrtowc() sets errno. */
51 				return ((size_t)-1);
52 			else if (nb == 0)
53 				return (nchr);
54 			s += nb;
55 			nchr++;
56 		}
57 		/*NOTREACHED*/
58 	}
59 
60 	while (len-- > 0) {
61 		if ((nb = (int)mbrtowc(dst, s, MB_CUR_MAX, NULL)) < 0) {
62 			*src = s;
63 			return ((size_t)-1);
64 		} else if (nb == 0) {
65 			*src = NULL;
66 			return (nchr);
67 		}
68 		s += nb;
69 		nchr++;
70 		dst++;
71 	}
72 	*src = s;
73 	return (nchr);
74 }
75