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);
When mode is zero, the fwide() function determines the current
orientation of stream. It returns a value > 0 if stream 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 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
Once a stream has an orientation, it cannot be changed and persists until
the stream is closed.
When mode is non-zero, the 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.
The 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.
ISO/ANSI C, POSIX.1-2001.
Wide-character output to a byte oriented stream can be performed through the
fprintf() function with the %lc and %ls directives.
Char oriented output to a wide-character oriented stream can be performed
through the fwprintf() function with the %c and %s directives.
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
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