import java.net.InetAddress; import java.net.UnknownHostException; public class WhoIs { /** * Find out ip/hostnames given a domain or IP. * * @param args domain you wish to lookup on the command line: * e.g. mindprod.com or 24.87.56.253. */ public static void main (String[] args) { if ( args.length == 1 ) { String domain = args[0]; try { InetAddress addr = InetAddress.getByName ( domain ); out.println( "main IP Address : " + addr.getHostAddress()); out.println( "main hostname : " + addr.getHostName() ); out.println(); InetAddress[] addrs = InetAddress.getAllByName ( domain ); for ( int i=0; i<addrs.length; i++ ) { if ( ! addrs[i].equals( addr ) ) { out.println( "alt IP Address : " + addrs[i].getHostAddress() ); out.println( "alt hostname : " + addrs[i].getHostName() ); out.println(); } } } catch ( UnknownHostException e ) { err.println( "Can't detect domain " + args +" : " + e ); } } else { out.println( "need domain or IP on command line e.g. mindprod.com or 24.87.56.253" ); } } }