_vcprintf_p, _vcprintf_p_l, _vcwprintf_p, _vcwprintf_p_l

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06/05/2017

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The latest version of this topic can be found at _vcprintf_p, _vcprintf_p_l, _vcwprintf_p, _vcwprintf_p_l.

Writes formatted output to the console by using a pointer to a list of arguments, and supports positional parameters in the format string.

Important

This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.

Syntax

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
The format specification.

argptr
A pointer to a list of arguments.

locale
The locale to use.

For more information, see Format Specification Syntax: printf and wprintf Functions.

Return Value

The number of characters that are 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, and then uses the _putch function to format and write the given data to the console. (_vcwprintf_p uses _putwch instead of _putch. _vcwprintf_p is the wide-character version of _vcprintf_p. It takes a wide-character string as an argument.)

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

Each argument (if any) is converted and is output according to the corresponding format specification in format. The format specification supports positional parameters so that you can specify 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 they are output.

Important

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

Tchar.h routine	_UNICODE and _MBCS not defined	_MBCS defined	_UNICODE defined
`_vtcprintf_p`	`_vcprintf_p`	`_vcprintf_p`	`_vcwprintf_p`
`_vtcprintf_p_l`	`_vcprintf_p_l`	`_vcprintf_p_l`	`_vcwprintf_p_l`

Requirements

Routine	Required header
`_vcprintf_p`, `_vcprintf_p_l`	<conio.h> and <stdarg.h>
`_vcwprintf_p`, `_vcwprintf_p_l`	<conio.h> and <stdarg.h>

For more compatibility information, see Compatibility.

Example

  
      // crt_vcprintf_p.c  
// compile with: /c  
#include <conio.h>  
#include <stdarg.h>  
  
// An error formatting function that's 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