code: private String[] readLine(BufferedReader r) throws IOException
  	{
  		System.out.print("> ");
  		final String line = r.readLine();
  		return line != null ? split(line) : null;
  	}
docs: Writes command prompt and waits for command request from user.
  <p>
  
  @param r input reader
  @return array with command and command arguments
  @throws IOException on I/O error