title: How do I get a list of active users with PHP?
body: <p>I currently maintain a DB table of users, when after logging in I update the table with their  ID and login_time. This works to a point but currently I can't tell if the user has been active since the login or for how long.</p>
  
  <p>Is there a better way to get a complete list of users that have been active in the past X minutes?</p>