I have read many php tutorials for logout scripts, i am wondering what could be the proper way to logout from a session!
Script 1
<?php
session_start();
session_destroy();
header("location:index.php");
?>
Script 2
<?php
session_start();
session_unset();
session_destroy();
header("location:index.php");
?>
Script 3
<?php
session_start();
if (isset($_SESSION['username']))
{
unset($_SESSION['username']);
}
header("location:index.php");
?>
Is there any more effective way to do this?? A session can always be created by logging back in, so should i bother about use of session_destroy() and use unset($_SESSION['variable']) instead? which one of the above 3 script is more preferable?
From the session_destroy() page in the PHP manual:
<?php
// Initialize the session.
// If you are using session_name("something"), don't forget it now!
session_start();
// Unset all of the session variables.
$_SESSION = array();
// If it's desired to kill the session, also delete the session cookie.
// Note: This will destroy the session, and not just the session data!
if (ini_get("session.use_cookies")) {
$params = session_get_cookie_params();
setcookie(session_name(), '', time() - 42000,
$params["path"], $params["domain"],
$params["secure"], $params["httponly"]
);
}
// Finally, destroy the session.
session_destroy();
?>
<?php
// Initialize the session.
session_start();
// Unset all of the session variables.
unset($_SESSION['username']);
// Finally, destroy the session.
session_destroy();
// Include URL for Login page to login again.
header("Location: login.php");
exit;
?>
Session_unset(); only destroys the session variables. To end the session there is another function called session_destroy(); which also destroys the session .
update :
In order to kill the session altogether, like to log the user out, the session id must also be unset. If a cookie is used to propagate the session id (default behavior), then the session cookie must be deleted. setcookie() may be used for that
Personally, I do the following:
session_start();
setcookie(session_name(), '', 100);
session_unset();
session_destroy();
$_SESSION = array();
That way, it kills the cookie, destroys all data stored internally, and destroys the current instance of the session information (which is ignored by session_destroy).
Source: Stackoverflow.com