#!/usr/bin/perl

use Socket;

if ( $#ARGV != 0 ) {

  print "$#ARGV\n";
  print "usage: $0 <xxx.xxx.xxx.xxx>\n";
  exit;

} else {

   $iaddr = inet_aton($ARGV[0]);
   $name  = gethostbyaddr($iaddr, AF_INET);

   print "$name\n";
}