title: get all keys set in memcached
body: <p>How can I get all the keys set in my memcached instance(s)?</p>
  
  <p>I tried googling, but didn't find much except that <code>PHP</code> supports a <a href="http://php.net/manual/en/memcached.getallkeys.php" rel="noreferrer"><code>getAllKeys</code> method</a>, which means it is actually possible to do this somehow. How can I get the same within a telnet session?</p>
  
  <p>I have tried out all the retrieval related options mentioned in <a href="http://www.lzone.de/articles/memcached.htm" rel="noreferrer">memcached cheat sheet</a> and <a href="http://blog.elijaa.org/?post/2010/05/21/Memcached-telnet-command-summary" rel="noreferrer">Memcached telnet command summary</a>, but none of them work and I am at a loss to find the correct way to do this.</p>
  
  <p>Note: I am currently doing this in development, so it can be assumed that there will be no issues due to new keys being set or other such race conditions happening, and the number of keys will also be limited.</p>