Port Scan Perl

use Socket;
$ARGC=@ARGV;
if ($ARGC<2)
{
      print "\nuso:$0 <host> <porta-inicial> <porta-final>\n\n";
   exit;
}


$porta_i=$ARGV[1];
$porta_f=$ARGV[2];

for(;$porta_i <= $porta_f;$porta_i++)
{
$iaddr= inet_aton($ARGV[0]);
$paddr= sockaddr_in($porta_i, $iaddr);
$proto= getprotobyname('tcp');
socket(SOCK, AF_INET, SOCK_STREAM, $proto);
   if(connect(SOCK, $paddr))
       {
      $servico=getservbyport($porta_i,'tcp');
      print "Porta $porta_i --> o servico $servico esta aberto\n";
      close(SOCK);
      }
}
print "\ntermino do scanner\n\n";
exit;