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

^[CX] 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.1-2024 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 .

EXAMPLES

None.

APPLICATION USAGE

Applications using these functions should call va_end(ap) afterwards to clean up.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

2.5 Standard I/O Streams , fwprintf

XBD <stdarg.h> , <stdio.h> , <wchar.h>

CHANGE HISTORY

First released in Issue 5. Included for alignment with ISO/IEC 9899:1990/Amendment 1:1995 (E).

Issue 6

The vfwprintf(), vswprintf(), and vwprintf() prototypes are updated for alignment with the ISO/IEC 9899:1999 standard.

Issue 7

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0705 [14] is applied.