C in a Nutshell

Name

vfwscanf, vswscanf, vwscanf

Synopsis

Reads formatted wide-character input using a variable argument list object

#include <stdarg.h>
#include <wchar.h>
intvswscanf( const wchar_t * restrict s, const wchar_t * restrict format,
              va_list argptr );
int vwscanf( const wchar_t * restrict format, va_list argptr );
#include <stdio.h>   // (in addition to <stdarg.h> and <wchar.h>)
int vfwscanf( FILE * restrict fp, const wchar_t * restrict format,
              va_list argptr );

The functions vfwscanf(), vswscanf(), and vwscanf() are like fwscanf(), swscanf(), and wscanf(), respectively, except that their final argument, argptr, is a variable-argument list object with type va_list. The program must initialize this object by calling the va_start() macro before calling the vfwscanf(), vswscanf(), or vwscanf() function, and must call the va_end() macro after the function returns. Because these functions use the va_arg() macro internally to advance the pointer through the argument list, its value is indeterminate after the vfwprintf(), vswprintf(), or vwprintf() function call has returned.

The vfwscanf(), vswscanf(), and vwscanf() functions return the number of input items assigned to variables, which may be 0; or EOF if an input failure occurs before any conversion takes place.

Example

See the example for the corresponding byte-character function vfscanf() in this chapter.

See Also

va_start(), va_arg(), va_copy() and va_end(); fwscanf(), swscanf(), and wscanf(); vfwprintf(), vswprintf(), and vwprintf()