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NAME

       fwide - set and determine the orientation of a FILE stream

SYNOPSIS

       #include <wchar.h>

       int fwide(FILE *stream, int mode);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       fwide():
	   _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE ||
	   _POSIX_C_SOURCE >= 200112L

DESCRIPTION

       When  mode is zero, the fwide() function determines the current orientation of stream.  It returns a positive value if stream is wide-char-
       acter 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 ori-
       ented--that  is,  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 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.

RETURN VALUE

       The fwide() function returns the stream's orientation, after possibly changing it.  A positive return value means wide-character  oriented.
       A negative return value means byte oriented.  A return value of zero means undecided.

CONFORMING TO

       POSIX.1-2001, POSIX.1-2008, C99.

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

       fprintf(3), fwprintf(3)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
								    2016-03-15								  FWIDE(3)