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

 int wprintf(const wchar_t * format , ...);
  int fwprintf(FILE * stream , const wchar_t * format , ...);   int swprintf(wchar_t * wcs , size_t  maxlen ,                 const wchar_t * format , ...); 

    #include <stdarg.h> 

    int vwprintf(const wchar_t * format , va_list  args );   int vfwprintf(FILE * stream , const wchar_t * format , va_list  args );   int vswprintf(wchar_t * wcs , size_t  maxlen ,                  const wchar_t * format , va_list  args ); 

The format string is a wide character string.

The output consists of wide characters, not bytes.

swprintf and vswprintf take a maxlen argument,
sprintf and vsprintf do not. (snprintf and vsnprintf
take a maxlen argument, but these functions do not return -1 upon
buffer overflow on Linux.)



The treatment of the conversion characters c and s is different:

c

If no
l modifier is present, the
int
argument is converted to a wide character by a call to the
btowc function, and the resulting wide character is written.
If an
l modifier is present, the
wint_t
(wide character) argument is written.

s

If no
l modifier is present: The
"" `` "const char *" ''
argument is expected to be a pointer to an array of character type
(pointer to a string) containing a multibyte character sequence beginning
in the initial shift state. Characters from the array are converted to
wide characters (each by a call to the
mbrtowc function with a conversion state starting in the initial state before
the first byte). The resulting wide characters are written up to
(but not including) the terminating null wide character. If a precision is
specified, no more wide characters than the number specified are written.
Note that the precision determines the number of
wide characters
written, not the number of
bytes
or
"screen positions" .
The array must contain a terminating null byte, unless a precision is given
and it is so small that the number of converted wide characters reaches it
before the end of the array is reached. -- If an
l modifier is present: The
"" `` "const wchar_t *" ''
argument is expected to be a pointer to an array of wide characters.
Wide characters from the array are written up to (but not including) a
terminating null wide character. If a precision is specified, no more than
the number specified are written. The array must contain a terminating null
wide character, unless a precision is given and it is smaller than or equal
to the number of wide characters in the array.