title: How to Count the number of active user in a website without using database or saving number in file using PHP
body: <p>How to Count the number of active user in a website without using database or saving number in file using PHP. </p>
  
  <p>ex. you and i are login/using a website how can i know that there are 2 active users in the wbsite?</p>
  
  <p>Does anyone know a function/method for this?</p>