newlib-cygwin/newlib/libc/time/wcsftime.c

69 lines
2.1 KiB
C

/*
* wcsftime.c
* Original Author: Craig Howland, for Newlib
*
* Source actually uses strftime.c.
* Documentation for wcsftime() here, with minimal overlap.
*/
/*
FUNCTION
<<wcsftime>>---convert date and time to a formatted wide-character string
INDEX
wcsftime
ANSI_SYNOPSIS
#include <time.h>
#include <wchar.h>
size_t wcsftime(wchar_t *<[s]>, size_t <[maxsize]>,
const wchar_t *<[format]>, const struct tm *<[timp]>);
DESCRIPTION
<<wcsftime>> is equivalent to <<strftime>>, except that:
O+
o The argument s points to the initial element of an array of wide characters
into which the generated output is to be placed.
o The argument maxsize indicates the limiting number of wide characters.
o The argument format is a wide-character string and the conversion specifiers
are replaced by corresponding sequences of wide characters.
o The return value indicates the number of wide characters.
O-
(The difference in all of the above being wide characters versus regular
characters.)
See <<strftime>> for the details of the format specifiers.
RETURNS
When the formatted time takes up no more than <[maxsize]> wide characters,
the result is the length of the formatted wide string. Otherwise, if the
formatting operation was abandoned due to lack of room, the result is
<<0>>, and the wide-character string starting at <[s]> corresponds to just those
parts of <<*<[format]>>> that could be completely filled in within the
<[maxsize]> limit.
PORTABILITY
C99 and POSIX require <<wcsftime>>, but do not specify the contents of
<<*<[s]>>> when the formatted string would require more than
<[maxsize]> characters. Unrecognized specifiers and fields of
<<timp>> that are out of range cause undefined results. Since some
formats expand to 0 bytes, it is wise to set <<*<[s]>>> to a nonzero
value beforehand to distinguish between failure and an empty string.
This implementation does not support <<s>> being NULL, nor overlapping
<<s>> and <<format>>.
<<wcsftime>> requires no supporting OS subroutines.
SEEALSO
<<strftime>>
*/
#include <time.h>
#include <wchar.h>
#define MAKE_WCSFTIME
#include "../time/strftime.c"