How can PHP developers implement a periodic cleanup process for removing inactive users from the online status tracking system without relying on external tools like cron jobs?

To implement a periodic cleanup process for removing inactive users from the online status tracking system without relying on external tools like cron jobs, PHP developers can create a script that runs whenever a user interacts with the system. This script can check the last activity timestamp of each user and remove those who have been inactive for a specified period.

// Check for inactive users and remove them
$inactive_period = 3600; // 1 hour of inactivity
$now = time();

// Query to get all users
$users = // Your query to retrieve users from the database

foreach ($users as $user) {
    if (($now - strtotime($user['last_activity'])) > $inactive_period) {
        // Remove the inactive user from the system
        // Your code to delete the user from the database
    }
}