//例10.1 WhoAml.java
import java.net.*;
public class tt
{
 public static void main(String[] args) throws Exception
 {
  if(args.length!=1)
  {
       System.err.println("Usage:WhoAml MachineName");
       System.exit(1);
  }
  InetAddress a=InetAddress.getByName(args[0]);
  System.out.println(a);
 }
}