title: Get keys under specific datatype in Redis
body: <p>I am new to Redis. Can I get somehow (or using a command)the keys under each data structure?
  For example:</p>
  <blockquote>
  <p>KEYS TYPE STRING</p>
  </blockquote>
  <ul>
  <li>keystr1</li>
  <li>keystr2</li>
  </ul>
  <blockquote>
  <p>KEYS TYPE SET</p>
  </blockquote>
  <ul>
  <li>keySet1</li>
  <li>keySet2</li>
  </ul>