20001017-2.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

void
fn_4parms (unsigned char a, long *b, long *c, unsigned int *d)
{
  if (*b != 1 || *c != 2 || *d != 3)
    abort ();
}

int
main ()
{
  unsigned char a = 0;
  unsigned long b = 1, c = 2;
  unsigned int d = 3;

  fn_4parms (a, &b, &c, &d);
  return 0;
}