Logout an inactive user using PHP

[jonlloydd]

I am trying to log a user out of my CMS after a set amount of time. By inactive I mean has not clicked the mouse or typed on there keyboard. So after 30 minutes of inactivity my log out function is ran.

There is already a log out function built in to the CMS I am using -

<?php
session_start();
if (isset($_SESSION['user_id'])){
    $login = 1;
}else{
    $login = 0;
}

function confirm_logged_in() {
    if (!isset($_SESSION['user_id'])) {
        //redirect
        header("Location: /_cms/login.php?login=0");
    }
}
function logout(){
        $_SESSION = array();
        if(isset($_COOKIE[session_name()])){
            setcookie(session_name(), '', time()-4200, '/');
        }   
        session_destroy();
}

?>

Someone else wrote this code and it works. However I don't know the exact time it takes to log out an inactive user. The preset time is - 4200. What I want to find out is how long that takes to logout and if I can change it to any time I want. Can anyone advise?

[tobyITguy]

The -4200 just sets the cookie expiration date to a date that has passed.

That way the cookie is deleted.

So changing the time in that particular function isn't gonna achieve what you want.

[jonlloydd]

Yes I have realised. I am trying something like this!

<?php
session_start();

function login(){
    //check login username/pass etc...
    $_SESSION['last_active_time'] = time();
}

function auth(){
   if($_SESSION['last_active_time'] < (time() - 180)){ //1800 is 30 minutes (time in seconds)
        logout(); //destroy the session in the logout function
    }
    else{
        $_SESSION['last_active_time'] = time();
    }
   //do some auth related things
}

function confirm_logged_in() {
    if (!isset($_SESSION['user_id'])) {
        //redirect
        header("Location: /_cms/login.php?login=0");
    }
}

function logout(){
        $_SESSION = array();
        if(isset($_COOKIE[session_name()])){
            setcookie(session_name(), '', time()-1800, '/');
        }   
        session_destroy();
}
?>

Howver this is doing nothing. It logs in and out fine, but it does not log out an inactive user after 30 minutes(as it should).

[tobyITguy]

You need to use javascript to determine mouse movement.
Your timer variable needs to be in javascript.

document.onmousemove = function(){your code here}

In your code you reset the timer every time the mouse moves.

Then you can make your javascript call your php function if the timer reaches 30mins without being reset.