_vcprintf_p, _vcprintf_p_l, _vcwprintf_p, _vcwprintf_p_l

Write formatted output to the console using a pointer to a list of arguments, with support for positional parameters in the format string.

int _vcprintf_p(
   const char* format,
   va_list argptr
);
int _vcprintf_p_l(
   const char* format,
   locale_t locale,
   va_list argptr
);
int _vcwprintf_p(
   const wchar_t* format,
   va_list argptr
);
int _vcwprintf_p_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 using the _putch function (_putwch for _vcwprintf_p). _vcwprintf_p is the wide-character version of _vcprintf_p. 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.

Each argument (if any) is converted and output according to the corresponding format specification in format. The format specification supports positional parameters, which allows specifying the order in which the arguments are used in the format string. For more information, see printf_p Positional Parameters.

These functions do not translate line-feed characters into carriage return–line feed (CR-LF) combinations when output.

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

These functions validate the input pointer and the format string. If format or argument is NULL, or if the format string contains invalid formatting characters, these functions invoke the invalid parameter handler, as described in Parameter Validation. If execution is allowed to continue, these functions return -1 and set errno to EINVAL.

Generic-Text Routine Mappings

Requirements

For more compatibility information, see Compatibility in the Introduction.

Example

// crt_vcprintf_p.c
// 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_p(format, args);
}

int main()
{
   int n = eprintf("parameter 2 = %2$d; parameter 1 = %1$s\r\n",
      "one", 222);
   _cprintf_s("%d characters printed\r\n");
}

parameter 2 = 222; parameter 1 = one
38 characters printed

See Also

Reference

Console and Port I/O

_cprintf, _cprintf_l, _cwprintf, _cwprintf_l

va_arg, va_end, va_start

printf_p Positional Parameters