I don't know the answer, but I suspect it might be OS-dependant. On which platforms will this run?

Update:

After much searching, I found a node on the topic.

I also came accross the module Win32::IPConfig:

use Win32::IPConfig ();

my $ipconfig = Win32::IPConfig->new();

foreach my $adapter ($ipconfig->get_adapters()) {
   foreach my $ip_addr ($adapter->get_ipaddresses()) {
      print("$ip_addr\n");
   }
}
[download]