vprintf, _vprintf_l, vwprintf, _vwprintf_l

مقالة
06/30/2010

Write formatted output using a pointer to a list of arguments.More secure versions of these functions are available, see vprintf_s, _vprintf_s_l, vwprintf_s, _vwprintf_s_l.

int vprintf(
   const char *format,
      va_list argptr 
);
int _vprintf_l(
      const char *format,
   locale_t locale,
   va_list argptr 
);
int vwprintf(
   const wchar_t *format,
   va_list argptr 
);
int _vwprintf_l(
   const wchar_t *format,
   locale_t locale,
   va_list argptr 
);

Parámetros

format
Format specification.
argptr
Pointer to list of arguments.
locale
The locale to use.

For more information, see Format Specifications.

Valor devuelto

vprintf and vwprintf return the number of characters written, not including the terminating null character, or a negative value if an output error occurs.If format is a null pointer, or if the format string contains invalid formatting characters, the invalid parameter handler is invoked, as described in Parameter Validation.If execution is allowed to continue, the functions return -1 and set errno to EINVAL.

For information on these and other error codes, see _doserrno, errno, _sys_errlist, and _sys_nerr.

Comentarios

Each of these functions takes a pointer to an argument list, then formats and writes the given data to stdout.

vwprintf is the wide-character version of vprintf; the two functions behave identically if the stream is opened in ANSI mode.vprintf doesn't currently support output into a UNICODE stream.

The versions of these functions with the _l suffix are identical except that they use the locale parameter passed in instead of the current thread locale.

Nota sobre la seguridad
Ensure that format is not a user-defined string.For more information, see Avoiding Buffer Overruns.The risk of using user-defined strings is much less in Visual C++ 2005, because invalid format strings are detected and result in an error.