Is use this way, but you need to declare a host for the machine, or you get 127.0.0.1:

  use Socket;
  use Sys::Hostname;
  my $host = hostname();
  my $address = inet_ntoa(scalar gethostbyname($host || 'localhost'));
  
  print "$host > $address\n" ;
[download]

For me this works on Linux and Win32, and I use a cable modem too.

Graciliano M. P.
"The creativity is the expression of the liberty".