wcsrtombs.c revision 129154 
1/*-
2 * Copyright (c) 2002-2004 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: head/lib/libc/locale/wcsrtombs.c 129154 2004-05-12 14:26:54Z tjr $");
29
30#include <limits.h>
31#include <stdlib.h>
32#include <string.h>
33#include <wchar.h>
34#include "mblocal.h"
35
36size_t
37wcsrtombs(char * __restrict dst, const wchar_t ** __restrict src, size_t len,
38    mbstate_t * __restrict ps)
39{
40	static mbstate_t mbs;
41	mbstate_t mbsbak;
42	char buf[MB_LEN_MAX];
43	const wchar_t *s;
44	size_t nbytes;
45	int nb;
46
47	s = *src;
48	nbytes = 0;
49
50	if (ps == NULL)
51		ps = &mbs;
52	if (dst == NULL) {
53		for (;;) {
54			if ((nb = (int)__wcrtomb(buf, *s, ps)) < 0)
55				/* Invalid character - wcrtomb() sets errno. */
56				return ((size_t)-1);
57			else if (*s == L'\0')
58				return (nbytes + nb - 1);
59			s++;
60			nbytes += nb;
61		}
62		/*NOTREACHED*/
63	}
64
65	while (len > 0) {
66		if (len > (size_t)MB_CUR_MAX) {
67			/* Enough space to translate in-place. */
68			if ((nb = (int)__wcrtomb(dst, *s, ps)) < 0) {
69				*src = s;
70				return ((size_t)-1);
71			}
72		} else {
73			/*
74			 * May not be enough space; use temp. buffer.
75			 *
76			 * We need to save a copy of the conversion state
77			 * here so we can restore it if the multibyte
78			 * character is too long for the buffer.
79			 */
80			mbsbak = *ps;
81			if ((nb = (int)__wcrtomb(buf, *s, ps)) < 0) {
82				*src = s;
83				return ((size_t)-1);
84			}
85			if (nb > (int)len) {
86				/* MB sequence for character won't fit. */
87				*ps = mbsbak;
88				break;
89			}
90			memcpy(dst, buf, nb);
91		}
92		if (*s == L'\0') {
93			*src = NULL;
94			return (nbytes + nb - 1);
95		}
96		s++;
97		dst += nb;
98		len -= nb;
99		nbytes += nb;
100	}
101	*src = s;
102	return (nbytes);
103}
104