fwide

FWIDE(3)		  Linux Programmer’s Manual		     FWIDE(3)



NAME
       fwide - set and determine the orientation of a FILE stream

SYNOPSIS
       #include <wchar.h>

       int fwide(FILE *stream, int mode);

DESCRIPTION
       When  mode is zero, the fwide function determines the current orienta-
       tion 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 dis-
       allowed. 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 oper-
       ation  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 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	 cur-
       rent orientation, as above.

RETURN VALUE
       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 zero means unde-
       cided.

CONFORMING TO
       ISO/ANSI C, UNIX98

SEE ALSO
       fprintf(3), fwprintf(3)

NOTES
       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 per-
       formed through the fwprintf function with the %c and %s directives.



GNU				  1999-11-17			     FWIDE(3)