FWIDE(3) NEWLIB FWIDE(3)NAME
4.30 `fwide'--set and determine the orientation of a FILE stream
SYNOPSIS
#include <wchar.h>
int fwide(FILE *FP, int MODE)
int _fwide_r(struct _reent *PTR, FILE *FP, int MODE)
DESCRIPTION
When MODE is zero, the `fwide' function determines the current orienta‐
tion of FP. It returns a value > 0 if FP is wide-character oriented,
i.e. if wide character I/O is permitted but char I/O is disallowed. It
returns a value < 0 if FP is byte oriented, i.e. if char I/O is permit‐
ted but wide character I/O is disallowed. It returns zero if FP 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, unless the stream is re-opened with fre‐
open, which removes the orientation of the stream.
When MODE is non-zero, the `fwide' function first attempts to set
FP'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.
RETURNS
The `fwide' function returns FP'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.
PORTABILITY
C99, POSIX.1-2001.
SEE ALSOfwide is part of the library. The full documentation for is maintained
as a Texinfo manual. If info and are properly installed at your site,
the command
info
will give you access to the complete manual.
NEWLIB April 2010 FWIDE(3)
