wcsnrtombs.c revision 132497 
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/wcsnrtombs.c 132497 2004-07-21 10:54:57Z 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
37wcsnrtombs(char * __restrict dst, const wchar_t ** __restrict src, size_t nwc,
38    size_t len, mbstate_t * __restrict ps)
39{
40	static mbstate_t mbs;
41
42	if (ps == NULL)
43		ps = &mbs;
44	return (__wcsnrtombs(dst, src, nwc, len, ps));
45}
46
47size_t
48__wcsnrtombs_std(char * __restrict dst, const wchar_t ** __restrict src,
49    size_t nwc, size_t len, mbstate_t * __restrict ps)
50{
51	mbstate_t mbsbak;
52	char buf[MB_LEN_MAX];
53	const wchar_t *s;
54	size_t nbytes;
55	size_t nb;
56
57	s = *src;
58	nbytes = 0;
59
60	if (dst == NULL) {
61		while (nwc-- > 0) {
62			if ((nb = __wcrtomb(buf, *s, ps)) == (size_t)-1)
63				/* Invalid character - wcrtomb() sets errno. */
64				return ((size_t)-1);
65			else if (*s == L'\0')
66				break;
67			s++;
68			nbytes += nb;
69		}
70		return (nbytes + nb - 1);
71	}
72
73	while (len > 0 && nwc-- > 0) {
74		if (len > (size_t)MB_CUR_MAX) {
75			/* Enough space to translate in-place. */
76			if ((nb = (int)__wcrtomb(dst, *s, ps)) < 0) {
77				*src = s;
78				return ((size_t)-1);
79			}
80		} else {
81			/*
82			 * May not be enough space; use temp. buffer.
83			 *
84			 * We need to save a copy of the conversion state
85			 * here so we can restore it if the multibyte
86			 * character is too long for the buffer.
87			 */
88			mbsbak = *ps;
89			if ((nb = (int)__wcrtomb(buf, *s, ps)) < 0) {
90				*src = s;
91				return ((size_t)-1);
92			}
93			if (nb > (int)len) {
94				/* MB sequence for character won't fit. */
95				*ps = mbsbak;
96				break;
97			}
98			memcpy(dst, buf, nb);
99		}
100		if (*s == L'\0') {
101			*src = NULL;
102			return (nbytes + nb - 1);
103		}
104		s++;
105		dst += nb;
106		len -= nb;
107		nbytes += nb;
108	}
109	*src = s;
110	return (nbytes);
111}
112