Section: Linux Programmer's Manual (3)
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fwide - set and determine the orientation of a FILE stream
int fwide(FILE *stream, int mode);
Feature Test Macro Requirements for glibc (see
_XOPEN_SOURCE >= 500 || _ISOC99_SOURCE ||
_ISOC95_SOURCE /* Since glibc 2.12 */ ||
_POSIX_C_SOURCE >= 200112L;
When mode is zero, the
function determines the current
orientation of stream.
It returns a positive value if stream is
wide-character oriented, that is, if wide-character I/O is permitted but char
I/O is disallowed.
It returns a negative value if stream is byte oriented,
i.e., if char I/O is permitted but wide-character I/O is disallowed.
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
Once a stream has an orientation, it cannot be changed and persists until
the stream is closed.
When mode is nonzero, the
function first attempts to set
stream's orientation (to wide-character oriented
if mode is greater than 0, or
to byte oriented if mode is less than 0).
It then returns a value denoting the
current orientation, as above.
function returns the stream's orientation, after possibly
A positive return value means wide-character oriented.
A negative return value means byte oriented.
A return value of zero means undecided.
Wide-character output to a byte oriented stream can be performed through the
function with the
Char oriented output to a wide-character oriented stream can be performed
function with the
This page is part of release 3.54 of the Linux
A description of the project,
and information about reporting bugs,
can be found at
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
This document was created by
using the manual pages.
Time: 23:29:01 GMT, January 18, 2018