xref: /freebsd/lib/libc/locale/wcstombs.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
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 wcstombs(char * __restrict s, const wchar_t * __restrict pwcs, size_t n)
48 {
49 	char buf[MB_LEN_MAX];
50 	char *e;
51 	int cnt, nb;
52 
53 	if (pwcs == NULL || n > INT_MAX) {
54 		errno = EINVAL;
55 		return (-1);
56 	}
57 
58 	cnt = 0;
59 
60 	if (s == NULL) {
61 		/* Convert and count only, do not store. */
62 		while (*pwcs != L'\0') {
63 			if (sputrune(*pwcs++, buf, MB_LEN_MAX, &e) == 0) {
64 				errno = EILSEQ;
65 				return (-1);
66 			}
67 			cnt += e - buf;
68 		}
69 		return (cnt);
70 	}
71 
72 	/* Convert, store and count characters. */
73 	nb = n;
74 	while (nb > 0) {
75 		if (*pwcs == L'\0') {
76 			*s = '\0';
77 			break;
78 		}
79 		if (sputrune(*pwcs++, s, nb, &e) == 0) {
80 			errno = EILSEQ;
81 			return (-1);
82 		}
83 		if (e == NULL)		/* too long */
84 			return (cnt);
85 		cnt += e - s;
86 		nb -= e - s;
87 		s = e;
88 	}
89 
90 	return (cnt);
91 }
92