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class StreamGobbler implements Runnable {
  private final InputStream is;
  private final PrintStream os;

  StreamGobbler(InputStream is, PrintStream os) {
    this.is = is;
    this.os = os;
  }

  public void run() {
    try {
      int c;
      while ((c = is.read()) != -1)
          os.print((char) c);
    } catch (IOException x) {
      // Handle error
    }
  }
}

public class Exec {
  public static void main(String[] args)
    throws IOException, InterruptedException {

    Runtime rt = Runtime.getRuntime();
    Process proc = rt.exec("notemaker");

    // Any error message?
    Thread errorGobbler
      = new Thread(new StreamGobbler(proc.getErrorStream(), System.err));
 
    // Any output?
    Thread outputGobbler
      = new Thread(new StreamGobbler(proc.getInputStream(), System.out));

    errorGobbler.start();
    outputGobbler.start();

    // Any error?
    int exitVal = proc.waitFor();
    errorGobbler.join();   // Handle condition where the
    outputGobbler.join();  // process ends before the threads finish
  }
}