_vcprintf, _vcprintf_l, _vcwprintf, _vcwprintf_l

Articolo
07/24/2011

Write formatted output to the console using a pointer to a list of arguments. More secure versions of these functions are available, see _vcprintf_s, _vcprintf_s_l, _vcwprintf_s, _vcwprintf_s_l.

int _vcprintf(
   const char* format,
   va_list argptr
);
int _vcprintf_l(
   const char* format,
   locale_t locale,
   va_list argptr
);
int _vcwprintf(
   const wchar_t* format,
   va_list argptr
);
int _vcwprintf_l(
   const wchar_t* format,
   locale_t locale,
   va_list argptr
);

Parameters

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

For more information, see Format Specifications.

Return Value

The number of characters written, or a negative value if an output error occurs. If format is a null pointer, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, errno is set to EINVAL and -1 is returned.

Remarks

Each of these functions takes a pointer to an argument list, then formats and writes the given data to the console. _vcwprintf is the wide-character version of _vcprintf. It takes a wide-character string as an argument.

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

Security Note
Ensure that format is not a user-defined string. For more information, see Avoiding Buffer Overruns.

Generic-Text Routine Mappings

TCHAR.H routine	_UNICODE & _MBCS not defined	_MBCS defined	_UNICODE defined
_vtcprintf	_vcprintf	_vcprintf	_vcwprintf
_vtcprintf_l	_vcprintf_l	_vcprintf_l	_vcwprintf_l

Requirements

Routine	Required header	Optional headers
_vcprintf, _vcprintf_l	<conio.h> and <stdarg.h>	<varargs.h>*
_vcwprintf, _vcwprintf_l	<conio.h> or <wchar.h>, and <stdarg.h>	<varargs.h>*

* Required for UNIX V compatibility.

For additional compatibility information, see Compatibility in the Introduction.

Example

// crt_vcprintf.cpp
// compile with: /c
#include <conio.h>
#include <stdarg.h>

// An error formatting function used to print to the console.
int eprintf(const char* format, ...)
{
  va_list args;
  va_start(args, format);
  return _vcprintf(format, args);
}

int main()
{
   eprintf("  (%d:%d): Error %s%d : %s\n", 10, 23, "C", 2111,
           "<some error text>");
   eprintf("  (Related to symbol '%s' defined on line %d).\n",
           "<symbol>", 5 );
}

  (10,23): Error C2111 : <some error text>
  (Related to symbol '<symbol>' defined on line 5).

.NET Framework Equivalent

System::Console::Write

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