fwide(3p) [posix man page]

FWIDE(3P)						     POSIX Programmer's Manual							 FWIDE(3P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       fwide -- set stream orientation

SYNOPSIS

       #include <stdio.h>
       #include <wchar.h>

       int fwide(FILE *stream, int mode);

DESCRIPTION

       The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here
       and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.

       The  fwide() function shall determine the orientation of the stream pointed to by stream.  If mode is greater than zero, the function first
       attempts to make the stream wide-oriented. If mode is less than zero, the function first attempts to make the stream byte-oriented.  Other-
       wise, mode is zero and the function does not alter the orientation of the stream.

       If the orientation of the stream has already been determined, fwide() shall not change it.

       The fwide() function shall not change the setting of errno if successful.

       Since  no  return  value is reserved to indicate an error, an application wishing to check for error situations should set errno to 0, then
       call fwide(), then check errno, and if it is non-zero, assume an error has occurred.

RETURN VALUE

       The fwide() function shall return a value greater than zero if, after the call, the stream has wide-orientation, a value less than zero	if
       the stream has byte-orientation, or zero if the stream has no orientation.

ERRORS

       The fwide() function may fail if:

       EBADF  The stream argument is not a valid stream.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       A call to fwide() with mode set to zero can be used to determine the current orientation of a stream.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of POSIX.1-2008, <stdio.h>, <wchar.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C)  2013  by	the  Institute	of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013								 FWIDE(3P)

Check Out this Related Man Page

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);

   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)

Linux and UNIX Man Pages

fwide(3p) [posix man page]

Check Out this Related Man Page