session_destroy
(PHP 4, PHP 5)
session_destroy — Destroys all data registered to a session
Description
session_destroy() destroys all of the data associated with the current session. It does not unset any of the global variables associated with the session, or unset the session cookie. To use the session variables again, session_start() has to be called.
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.
Return Values
Returns TRUE on success or FALSE on failure.
Examples
Example #1 Destroying a session with $_SESSION
<?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();
?>
Notes
Note:
Only use session_unset() for older deprecated code that does not use $_SESSION.
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для работы с сессиями
- Управление сессиями
- session_abort
- session_cache_expire
- session_cache_limiter
- session_commit
- session_create_id
- session_decode
- session_destroy
- session_encode
- session_gc
- session_get_cookie_params
- session_id
- session_is_registered
- session_module_name
- session_name
- session_regenerate_id
- session_register_shutdown
- session_register
- session_reset
- session_save_path
- session_set_cookie_params
- session_set_save_handler
- session_start
- session_status
- session_unregister
- session_unset
- session_write_close
Коментарии
If you want to change the session id on each log in, make sure to use session_regenerate_id(true) during the log in process.
<?php
session_start();
session_regenerate_id(true);
?>
[Edited by moderator (googleguy at php dot net)]
It took me a while to figure out how to destroy a particular session in php. Note I'm not sure if solution provided below is perfect but it seems work for me. Please feel free to post any easier way to destroy a particular session. Because it's quite useful for functionality of force an user offline.
1. If you're using db or memcached to manage session, you can always delete that session entry directly from db or memcached.
2. Using generic php session methods to delete a particular session(by session id).
<?php
$session_id_to_destroy = 'nill2if998vhplq9f3pj08vjb1';
// 1. commit session if it's started.
if (session_id()) {
session_commit();
}
// 2. store current session id
session_start();
$current_session_id = session_id();
session_commit();
// 3. hijack then destroy session specified.
session_id($session_id_to_destroy);
session_start();
session_destroy();
session_commit();
// 4. restore current session id. If don't restore it, your current session will refer to the session you just destroyed!
session_id($current_session_id);
session_start();
session_commit();
?>
I found out that in order to really have the session data cleared after calling session_destroy(), you need to refresh the page. For example by calling
header('Location: '.$_SERVER['PHP_SELF']."?page=profile");
if you don't then there are still data in $_SESSION which was there before. I don't know if this is intended behavior but it's kind of confusing IMO...