Working With Sessions

daredevil14

Hey, i am working with the following "number_of_online_users" script, here's the code :

<?php

session_start();

function getusersonline() 
{
   $count = 0; 

   $handle = opendir(session_save_path());
   if ( $handle == false ) 
   {
   return -1;
   } 

   while ( ($file = readdir($handle)) != false ) 
   {
   if ( ereg("^sess", $file) ) 
     {
     $count++;
     }
   }

   closedir($handle); 
   return $count;

}

$usercount = getusersonline();
echo "Number Of Online Users : ". $usercount; 

?>

the problem is simple, it always increase the number even if the user closes the site, and not decrease it by either the departure of the user from the site or by the expiration of the session... i wanna alter this code to decrease our number of online users when he/she leaves the site, any idea ?

// //

my second question is about the expiration of the sessions, for example, i want from the following script to the session to be expired after 5 minutes, but it is not expiring, why ?

<?php

session_cache_expire(5);

session_start();

if ( !isset($_SESSION["admin"]) || empty($_SESSION["admin"]) )
  {
  echo "You Are Not Allowed To See This Page<p>| <a href=\"home.php\">Home</a> |</p>";
  }
  else
  {
  echo "Welcome " . $_SESSION["admin"] . " To Your Administration Panel";
  echo "<br /><br />";
  echo "| <a href=\"admin_logout.php\">Logout</a> |";
  }

?>

and what about the : session_cache_limiter('private'); ? what is it ?
and the : session.gc_maxlifetime ? what is it ?

Regards

daredevil14

Any reply ?

bradgrafelman

You can read up on the process in the manual ([man]session[/man]), but in essence, PHP doesn't perform "garbage collection" (the process where old session files that have been left inactive for a specified period of time are deleted) every second. You should visit the manual and read up on what the session.gc_probability and session.gc_divisor directives do.

As a side note, you might want to consider using a database to count the number of online users as counting session files isn't generally the recommended practice.