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Commit	Line	Data
	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: src/lib/libc/locale/wcsftime.c,v 1.4 2004/04/07 09:47:56 tjr Exp $");
	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	*/
	49	size_t
	50	wcsftime(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;
	54	mbstate_t mbs;
	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	*/
	65	mbs = initial;
	66	sflen = wcsrtombs(NULL, &format, 0, &mbs);
	67	if (sflen == (size_t)-1)
	68	goto error;
	69	if ((sformat = malloc(sflen + 1)) == NULL)
	70	goto error;
	71	mbs = initial;
	72	wcsrtombs(sformat, &format, sflen + 1, &mbs);
	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;
	89	dstp = dst;
	90	mbs = initial;
	91	n = mbsrtowcs(wcs, (const char **)&dstp, maxsize, &mbs);
	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
	99	error:
	100	sverrno = errno;
	101	free(sformat);
	102	free(dst);
	103	errno = sverrno;
	104	return (0);
	105	}