How to logout from site? - codeigniter

Question

How to logout from all pages of view, when I click on logout link I just from only one page when I am trying to logout from another page its not work.
My controller code is:
public function do_login()
{
$this->user = $this->input->post('user_email',TRUE);
$this->pass = $this->input->post('user_pass',TRUE);
$this->pass=md5(sha1(sha1($this->pass)));
$u = new User();
$login_data = array('email' => $this->user, 'password' => $this->pass);
$u->where($login_data)->get();
if(!empty($u->id) && $u->id > 0 )
{
$_SESSION['user_id'] = $u->id;
$_SESSION['user_name']= $u->username;
$_SESSION['fullname']= $u->fullname;
$_SESSION['is_verefied'] = $u->active;
$_SESSION['user_email']= $u->email;
$u->lastlogin = time();
$u->save();
setcookie("logged", 1, time()+86400);
if(empty($_POST['referer']))
{
if(empty($_GET['referer']))
{
$url = "./";
}
else
{
$url = $_GET['referer'];
}
}
else
{
$url = $_POST['referer'];
}
redirect($url);
}
else
{
$this->template->set_layout('inner');
$this->template->build('login_view',$this->data);
}
}
public function logout()
{
setcookie("logged", 0, time()+86400);
$_COOKIE["logged"] = '';
$_SESSION['user_id'] = '';
$_SESSION['user_name']= '';
$_SESSION['fullname']= '';
$_SESSION['is_verefied'] = '';
$_SESSION['user_email']= '';
redirect('./home/index/logout');
}
When I logout from site, and click back from browser the user information session its not deleted.

Answer 1

The back button of your browser might get you to cached version of you page, cached from back when you were logged it. Also, I suggest you use CodeIgniter's sessions.
To make sure you're doing everything right.
Destroy the session:
$this->session->sess_destroy();
Clear the cookie, make sure you use the same domain as when you set it up, and that the time is set to past:
setcookie('logged', '', time()-3600); // minus one hour

Answer 2

This script will log the user out of all pages that have a session started on them. You know a page uses sessions if this code is at the top of the code for that page:
<?php session_start(); ?>
Logging out of a website is simply clearing any session data and then destroying it.
Try the following in your logout.php:
<?php
session_start();
// what were doing here is checking for any cookies used by the session.
//If there are any, we are going to delete the data with it.
if (ini_get("session.use_cookies")) {
$params = session_get_cookie_params();
setcookie(session_name(), '', time() - 42000,
$params["path"], $params["domain"],
$params["secure"], $params["httponly"]
);
}
//now lets unset the session and destroy it
session_unset();
session_destroy();
// for the redirect, we simple use the php header to send the redirect url to the browser
header("Location: login");
Make sure when using the header function that there is no output, caused by blank spaces or html. As a logout page, there should be no output anyways since navigating to the logout page should log the user out and immediately redirect.
I use this script on all my sites and it works great. Anywhere I want the logout link to appear, I just link to the page as such:
Logout
Just make a file called logout.php and put this code into it.
Hope this helps you!