conversion double -> char

/* ECVT.C: This program uses _ecvt to convert a
 * floating-point number to a character string.
 */

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
   int     decimal,   sign;
   char    *buffer;
   int     precision = 10;
   double  source = 3.1415926535;

   buffer = _ecvt( source, precision, &decimal, &sign );
   printf( "source: %2.10f   buffer: '%s'  decimal: %d  sign: %d\n",
           source, buffer, decimal, sign );
}

Output

source: 3.1415926535   buffer: '3141592654'  decimal: 1   sign: 0