NAME
fwide - set and determine the orientation of a FILE stream
SYNOPSIS
#include <wchar.h>
I int fwide(FILE * stream , int mode );
DESCRIPTION
When mode is zero, the
R fwide ()
function determines the current
orientation of stream.
It returns a value > 0 if stream is
wide-character oriented, that is, if wide-character I/O is permitted but char
I/O is disallowed.
It returns a value < 0 if stream is byte oriented,
i.e. if char I/O is permitted but wide-character I/O is disallowed.
It
returns zero if stream has no orientation yet; in this case the next
I/O operation might change the orientation (to byte oriented if it is a char
I/O operation, or to wide-character oriented if it is a wide-character I/O
operation).
Once a stream has an orientation, it cannot be changed and persists until
the stream is closed.
When mode is non-zero, the
R fwide ()
function first attempts to set
stream's orientation (to wide-character oriented if mode > 0, or
to byte oriented if mode < 0).
It then returns a value denoting the
current orientation, as above.
RETURN VALUE
The
R fwide ()
function returns the stream's orientation, after possibly
changing it.
A return value > 0 means wide-character oriented.
A return value
< 0 means byte oriented.
A return value of zero means undecided.
CONFORMING TO
C99, POSIX.1-2001.
NOTES
Wide-character output to a byte oriented stream can be performed through the
fprintf(3)
function with the %lc and %ls directives.
Char oriented output to a wide-character oriented stream can be performed
through the
fwprintf(3)
function with the %c and %s directives.
SEE ALSO
