title: why download only for apt-get cron job
body: <p>I'm putting a crontab job for updating with apt-get once a day (running Debian Lenny, there are updates almost daily). But almost all examples i've seen of this cron job invoke the -d flag. </p>
  
  <p>This elicits 4 questions:</p>
  
  <ul>
  <li>Why should I only download the
  packages and not install them?</li>
  <li>Doesn't this defeat the purpose of
  running it automatically?</li>
  <li>Don't I have to go in and actually
  install the updates later?</li>
  <li>Is it safe for me to run the cron
  job without the -d flag?</li>
  </ul>