my $dd = "hello world\n";
printf("the dd string address is %x \n", cc($dd));
use Inline 'C' => <<'CODE';
 unsigned int cc(SV* a){
 40 return SvPVX(a);
 41 }
 42 CODE

# just print the dd string address is 8d8b8e90, the upper 4bytes of the address was truncated.