#include <math.h>
#include <stdio.h>                 /* for printf */
void tst_modf (void) {
   float x;
   float int_part, frc_part;
   x = 123.456;
   frc_part = modf (x, &int_part);
   printf ("%f = %f + %f\n", x, int_part,frc_part);
}