VFWPRINTF(3)               POSIX Programmer's Manual              VFWPRINTF(3)



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

NAME
       vfwprintf, vswprintf, vwprintf -- wide-character formatted output of a
       stdarg argument list

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

       int vfwprintf(FILE *restrict stream, const wchar_t *restrict format,
           va_list arg);
       int vswprintf(wchar_t *restrict ws, size_t _n,
           const wchar_t *restrict format, va_list arg);
       int vwprintf(const wchar_t *restrict format, va_list arg);

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.1-2017
       defers to the ISO C standard.

       The vfwprintf(), vswprintf(), and vwprintf() functions shall be
       equivalent to fwprintf(), swprintf(), and wprintf() respectively,
       except that instead of being called with a variable number of
       arguments, they are called with an argument list as defined by
       <stdarg.h>.

       These functions shall not invoke the va__end macro. However, as these
       functions do invoke the va__arg macro, the value of ap after the return
       is unspecified.

RETURN VALUE
       Refer to fwprintf().

ERRORS
       Refer to fwprintf().

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Applications using these functions should call va__end(ap) afterwards to
       clean up.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Section 2.5, Standard I/O Streams, fwprintf()

       The Base Definitions volume of POSIX.1-2017, <stdarg.h>, <stdio.h>,
       <wchar.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  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 Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/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                  2017                         VFWPRINTF(3)
