_scprintf, _scprintf_l, _scwprintf, _scwprintf_l

Returns the number of characters in the formatted string.

int _scprintf(
   const char *format [,
   argument] ... 
int _scprintf_l(
   const char *format,
   locale_t locale [,
   argument] ... 
int _scwprintf(
   const wchar_t *format [,
   argument] ... 
int _scwprintf_l(
   const wchar_t *format,
   locale_t locale [,
   argument] ... 


Format-control string.


Optional arguments.


The locale to use.

For more information, see Format Specifications.

Returns the number of characters that would be generated if the string were to be printed or sent to a file or buffer using the specified formatting codes. The value returned does not include the terminating null character. _scwprintf performs the same function for wide characters.

If format is a NULL pointer, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, these functions return -1 and set errno to EINVAL.

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

Each argument (if any) is converted according to the corresponding format specification in format. The format consists of ordinary characters and has the same form and function as the format argument for printf.

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.

Security note Security Note

Ensure that format is not a user-defined string.

Generic-Text Routine Mappings

Tchar.h routine

_UNICODE and _MBCS not defined

_MBCS defined

_UNICODE defined










Required header

_scprintf , _scprintf_l


_scwprintf , _scwprintf_l

<stdio.h> or <wchar.h>

For more compatibility information, see Compatibility in the Introduction.

// crt__scprintf.c


#include <stdio.h>
#include <math.h>
#include <malloc.h>

int main( void )
   int count;
   int size;
   char *s = NULL;

   count = _scprintf( "The value of Pi is calculated to be %f.\n",

   size = count + 1; // the string will need one more char for the null terminator
   s = malloc(sizeof(char) * size);
   sprintf_s(s, size, "The value of Pi is calculated to be %f.\n",
   printf("The length of the following string will be %i.\n", count);
   printf("%s", s);
   free( s );
The length of the following string will be 46.
The value of Pi is calculated to be 3.141593.