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author | tjr <tjr@FreeBSD.org> | 2002-09-11 08:57:11 +0000 |
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committer | tjr <tjr@FreeBSD.org> | 2002-09-11 08:57:11 +0000 |
commit | 5f5cd9d0b813ebc54b63008e1ccea578606e81e4 (patch) | |
tree | 8c2f74f436cd6ea0913a007054c0425995e4696f /lib/libc/locale/wcsftime.c | |
parent | 8985bac5bf6628b54821fe8b9fdf6156bb24a1eb (diff) | |
download | FreeBSD-src-5f5cd9d0b813ebc54b63008e1ccea578606e81e4.zip FreeBSD-src-5f5cd9d0b813ebc54b63008e1ccea578606e81e4.tar.gz |
Add an implementation of wcsftime() (wide character version of strftime()).
Diffstat (limited to 'lib/libc/locale/wcsftime.c')
-rw-r--r-- | lib/libc/locale/wcsftime.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/lib/libc/locale/wcsftime.c b/lib/libc/locale/wcsftime.c new file mode 100644 index 0000000..31a1c4c --- /dev/null +++ b/lib/libc/locale/wcsftime.c @@ -0,0 +1,87 @@ +/*- + * Copyright (c) 2002 Tim J. Robbins + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <limits.h> +#include <stdlib.h> +#include <time.h> +#include <wchar.h> + +/* + * Convert date and time to a wide-character string. + * + * This is the wide-character counterpart of strftime(). So that we do not + * have to duplicate the code of strftime(), we convert the format string to + * multibyte, call strftime(), then convert the result back into wide + * characters. + * + * This technique loses in the presence of stateful multibyte encoding if any + * of the conversions in the format string change conversion state. When + * stateful encoding is implemented, we will need to reset the state between + * format specifications in the format string. + */ +size_t +wcsftime(wchar_t * __restrict wcs, size_t maxsize, + const wchar_t * __restrict format, const struct tm * __restrict timeptr) +{ + static const mbstate_t initial; + mbstate_t state; + char *dst, *sformat; + size_t n, sflen; + + /* + * Convert the supplied format string to a multibyte representation + * for strftime(), which only handles single-byte characters. + */ + state = initial; + sflen = wcsrtombs(NULL, &format, 0, &state); + if (sflen == (size_t)-1) + return (0); + sformat = alloca(sflen + 1); + state = initial; + wcsrtombs(sformat, &format, sflen + 1, &state); + + /* + * Allocate memory for longest multibyte sequence that will fit + * into the caller's buffer and call strftime() to fill it. + * Then, copy and convert the result back into wide characters in + * the caller's buffer. + */ + if (SIZE_T_MAX / MB_CUR_MAX <= maxsize) + /* maxsize is prepostorously large - avoid int. overflow. */ + return (0); + dst = alloca(maxsize * MB_CUR_MAX); + if (strftime(dst, maxsize, sformat, timeptr) == 0) + return (0); + state = initial; + n = mbsrtowcs(wcs, (const char **)&dst, maxsize, &state); + if (n == (size_t)-2 || n == (size_t)-1 || dst != NULL) + return (0); + + return (n); +} |