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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>
3d9156a7 28__FBSDID("$FreeBSD: src/lib/libc/locale/wcsftime.c,v 1.4 2004/04/07 09:47:56 tjr Exp $");
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29
30#include <errno.h>
31#include <limits.h>
32#include <stdlib.h>
33#include <time.h>
34#include <wchar.h>
35
36/*
37 * Convert date and time to a wide-character string.
38 *
39 * This is the wide-character counterpart of strftime(). So that we do not
40 * have to duplicate the code of strftime(), we convert the format string to
41 * multibyte, call strftime(), then convert the result back into wide
42 * characters.
43 *
44 * This technique loses in the presence of stateful multibyte encoding if any
45 * of the conversions in the format string change conversion state. When
46 * stateful encoding is implemented, we will need to reset the state between
47 * format specifications in the format string.
48 */
49size_t
50wcsftime(wchar_t * __restrict wcs, size_t maxsize,
51 const wchar_t * __restrict format, const struct tm * __restrict timeptr)
52{
53 static const mbstate_t initial;
3d9156a7 54 mbstate_t mbs;
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55 char *dst, *dstp, *sformat;
56 size_t n, sflen;
57 int sverrno;
58
59 sformat = dst = NULL;
60
61 /*
62 * Convert the supplied format string to a multibyte representation
63 * for strftime(), which only handles single-byte characters.
64 */
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65 mbs = initial;
66 sflen = wcsrtombs(NULL, &format, 0, &mbs);
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67 if (sflen == (size_t)-1)
68 goto error;
69 if ((sformat = malloc(sflen + 1)) == NULL)
70 goto error;
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71 mbs = initial;
72 wcsrtombs(sformat, &format, sflen + 1, &mbs);
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73
74 /*
75 * Allocate memory for longest multibyte sequence that will fit
76 * into the caller's buffer and call strftime() to fill it.
77 * Then, copy and convert the result back into wide characters in
78 * the caller's buffer.
79 */
80 if (SIZE_T_MAX / MB_CUR_MAX <= maxsize) {
81 /* maxsize is prepostorously large - avoid int. overflow. */
82 errno = EINVAL;
83 goto error;
84 }
85 if ((dst = malloc(maxsize * MB_CUR_MAX)) == NULL)
86 goto error;
87 if (strftime(dst, maxsize, sformat, timeptr) == 0)
88 goto error;
9385eb3d 89 dstp = dst;
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90 mbs = initial;
91 n = mbsrtowcs(wcs, (const char **)&dstp, maxsize, &mbs);
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92 if (n == (size_t)-2 || n == (size_t)-1 || dstp != NULL)
93 goto error;
94
95 free(sformat);
96 free(dst);
97 return (n);
98
99error:
100 sverrno = errno;
101 free(sformat);
102 free(dst);
103 errno = sverrno;
104 return (0);
105}