Process.waitfor () does not return correct value. In the little example below,
when "ping" is exec'ed on a standalone machine it should always return an
exit result of '1', i.e. "failed". Instead, when done repeatedly 'waitfor'
returns a semi-random sequence of 1's and 0's.

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import java.lang.Runtime;
import java.lang.Process;

public class Test {
  
  public static void main (String args[])
    {
      String execArgs[] = {"ping", "webcache.eng", "3"};
      Process proc;
      byte buffer[] = new byte[1024];

      try {
        while (true) {
          proc = Runtime.getRuntime().exec (execArgs);
          int result = proc.waitFor ();
          System.out.print ("Ping = " + result + " -- ");
          System.out.write (buffer, 0, proc.getInputStream().read(buffer));
          proc.destroy ();
        }
      } catch (java.io.IOException ex) {
        return;
      } catch (java.lang.InterruptedException ex) {
        return;
      }
    }
}