vfwprintf

Writes output to the stream under control of the wide-character format string.

Format

#include  <wchar.h>

int vfwprintf  (FILE *stream, const wchar_t
               *format, va_list arg);

Arguments

stream

A file pointer.

format

A pointer to a wide-character string containing the format specifications. For more information about format and conversion specifications and their corresponding arguments, see Chapter 2.

arg

A variable list of the items needed for output.

Description

If the stream pointed to by stream has no orientation, vfwprintf makes the stream wide-oriented.

See also fwprintf in this section

Return Values

n

The number of wide characters written.

Negative value

Indicates an error. The function sets errno to one of the following: EILSEQ - Invalid character detected. EINVAL - Insufficient arguments. ENOMEM - Not enough memory available for conversion. ERANGE - Floating-point calculations overflow. EVMSERR - Nontranslatable VMS error. vaxc$errno contains the VMS error code. This might indicate that conversion to a numeric value failed because of overflow. The function can also set errno to the following as a result of errors returned from the I/O subsystem: EBADF - The file descriptor is not valid. EIO - I/O error. ENOSPC - No free space on the device containing the file. ENXIO - Device does not exist. EPIPE - Broken pipe. ESPIPE - Illegal seek in a file opened for append. EVMSERR - Nontranslatable VMS error. vaxc$errno contains the VMS error code. This indicates that an I/O error occurred for which there is no equivalent C error code.

Examples

The following example shows the use of the vfwprintf function in a general error reporting routine.

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

 void error(char *function_name, wchar_t *format,  . . . );
 {
    va_list args;

    va_start(args, format);
    /* print out name of function causing error */
    fwprintf(stderr, L"ERROR in %s: ", function_name);
    /* print out remainder of message */
    vfwprintf(stderr, format, args);
    va_end(args);
 }