NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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

NAME         top

       fwide - set and determine the orientation of a FILE stream

SYNOPSIS         top

       #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         top

       When mode is zero, the fwide() 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—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         top

       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         top

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

NOTES         top

       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         top

       fprintf(3), fwprintf(3)

COLOPHON         top

       This page is part of release 4.08 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)