On browser close logout - php

Question

There are many questions asked about this problem but i suppose none of them could help me in my case. I will show you my login form , my main page, showing active users , and am little confused about starting lastTimeUpdate function to it.
Here is my main contetnt form, the problem is that there is a list of active users if user is active his name is displayed if not - not displayed, but if user exits browser, session destroys, but doesnt log out:
<?php
include 'config.php';
//include 'logout.php';
$query = "SELECT * FROM userinfo WHERE `ifactive` = 1";
if(isset($_SESSION['uname'])){
$result = mysql_query($query);
echo "<div id=maincontenttopleft>
<p>Active users</p>";
echo "<div id=acuser><table id=activeusers>";
while($row = mysql_fetch_array($result)){
echo "</td><td>" . $row['name'] . "</td></tr>";
}
echo "</table></div>";
mysql_close();
}
//if (session_destroy()) {
//mysql_query("SELECT * FROM `userinfo` WHERE `ifactive` = 1 AND `uname` !=
'$_SESSION[uname]'");
//mysql_query("UPDATE `userinfo` SET `ifactive` = 0 WHERE `uname` !=
'$_SESSION[uname]'") or die(mysql_error());
//}
if (!isset($_SESSION['uname'])) {
$_SESSION['uname'] = time();
} else if (time() - $_SESSION['uname'] > 10) {
// session started more than 30 minutes ago
//mysql_query("SELECT * FROM `userinfo` WHERE `ifactive` = 1 AND `uname` =
'$_SESSION[uname]'");
//mysql_query("UPDATE `userinfo` SET `ifactive` = 0 WHERE `uname` =
'$_SESSION[uname]'") or die(mysql_error());
session_regenerate_id(true); // change session ID for the current session an
invalidate old session ID
$_SESSION['uname'] = time(); // update creation time
}
?>
I want to check if there is a destroyed session, to take the name of this session end according to the name to set my boolean (ifactive) to zero. Can you help me about the logic of it.

Answer 1

You'll then need to save the session_id of every user in the database.
And then inside a cron for instance, have a script checking the existence of the file associated to each session.
Here is how you find your sessions folder if you don't want to mess in your config files :
<?php
echo session_save_path ();
?>
Your cron script could then save the results in a txt file which would be easier for your website script to read (or better yet, save it in memory so it's faster - checkout redis).