1 /* $NetBSD: wcsftime.c,v 1.3 2007/05/21 15:32:17 tnozaki Exp $ */ 2 /*- 3 * Copyright (c) 2002 Tim J. Robbins 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #if defined(LIBC_SCCS) && !defined(lint) 30 #if 0 31 __FBSDID("$FreeBSD: src/lib/libc/locale/wcsftime.c,v 1.4 2004/04/07 09:47:56 tjr Exp $"); 32 #else 33 __RCSID("$NetBSD: wcsftime.c,v 1.3 2007/05/21 15:32:17 tnozaki Exp $"); 34 #endif 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <errno.h> 38 #include <limits.h> 39 #include <stdlib.h> 40 #include <time.h> 41 #include <wchar.h> 42 43 /* 44 * Convert date and time to a wide-character string. 45 * 46 * This is the wide-character counterpart of strftime(). So that we do not 47 * have to duplicate the code of strftime(), we convert the format string to 48 * multibyte, call strftime(), then convert the result back into wide 49 * characters. 50 * 51 * This technique loses in the presence of stateful multibyte encoding if any 52 * of the conversions in the format string change conversion state. When 53 * stateful encoding is implemented, we will need to reset the state between 54 * format specifications in the format string. 55 */ 56 size_t 57 wcsftime(wchar_t *wcs, size_t maxsize, 58 const wchar_t *format, const struct tm *timeptr) 59 { 60 char *dst, *dstp, *sformat; 61 size_t n, sflen; 62 int sverrno; 63 64 sformat = dst = NULL; 65 66 /* 67 * Convert the supplied format string to a multibyte representation 68 * for strftime(), which only handles single-byte characters. 69 */ 70 sflen = wcstombs(NULL, format, 0); 71 if (sflen == (size_t)-1) 72 goto error; 73 if ((sformat = malloc(sflen + 1)) == NULL) 74 goto error; 75 wcstombs(sformat, format, sflen + 1); 76 77 /* 78 * Allocate memory for longest multibyte sequence that will fit 79 * into the caller's buffer and call strftime() to fill it. 80 * Then, copy and convert the result back into wide characters in 81 * the caller's buffer. 82 */ 83 if (SIZE_T_MAX / MB_CUR_MAX <= maxsize) { 84 /* maxsize is preposterously large - avoid int. overflow. */ 85 errno = EINVAL; 86 goto error; 87 } 88 dst = malloc(maxsize * MB_CUR_MAX); 89 if (dst == NULL) 90 goto error; 91 if (strftime(dst, maxsize, sformat, timeptr) == 0) 92 goto error; 93 dstp = dst; 94 n = mbstowcs(wcs, dstp, maxsize); 95 if (n == (size_t)-2 || n == (size_t)-1) 96 goto error; 97 98 free(sformat); 99 free(dst); 100 return n; 101 102 error: 103 sverrno = errno; 104 free(sformat); 105 free(dst); 106 errno = sverrno; 107 return 0; 108 } 109