This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
vfwprintf, vswprintf, vwprintf — wide-character formatted output of a stdarg argument list
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);
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 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.
Refer to fwprintf().
The following sections are informative.
Applications using these functions should call va_end(ap) afterwards to clean up.
Section 2.5, Standard I/O Streams, fwprintf()
The Base Definitions volume of POSIX.1‐2008, <stdarg.h>, <stdio.h>, <wchar.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology -- 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 Standard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .
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