You can take this code.

Just foreach() the online users and apply the mentioned code, e.g.:

elgg_call(ELGG_IGNORE_ACCESS, function () use (&$users) {

    foreach ($users as $user) {
           _elgg_services()->persistentLogin->removePersistentLogin();
           
           $old_msg = _elgg_services()->session->get(SystemMessagesService::SESSION_KEY, []);

          _elgg_services()->session->invalidate();

          _elgg_services()->session_manager->getLoggedInUser() = null;

          _elgg_services()->set(SystemMessagesService::SESSION_KEY, $old_msg);

         _elgg_services()->events->triggerAfter('logout', 'user', $user);

    }

    return true;

});

@Nikolai

That wouldn't work as the session (and session manager) only apply to the logged in user. There is no way that those services can touch other sessions (luckily).

@Hermand

What is your goal? If you wish to perform some maintenance to the server and don't want to have any users only. Simply enable Maintenance mode from the admin side.

With a bit of programming you can truncate the users_sessions table and therefor nobody will be logged in anymore (maybe also truncate the users_remember_me_cookies table to not automatically let users log back in who have Remember me enabled)

@Jerome  I assumed this

@jeabakker and @rivervanrain thanks a a lot I will simply enable Maintenance mode from the admin side.