Provided by: manpages-dev_2.77-1_all
fwide - set and determine the orientation of a FILE stream
int fwide(FILE *stream, int mode);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
fwide(): _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE; or cc -std=c99
When mode is zero, the 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 nonzero, 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
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
This page is part of release 2.77 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.