How to set lifetime of session

Set following php parameters to same value in seconds:

session.cookie_lifetime
session.gc_maxlifetime

in php.ini, .htaccess or for example with

ini_set('session.cookie_lifetime', 86400);
ini_set('session.gc_maxlifetime', 86400);

for a day.

Links:

http://www.php.net/manual/en/session.configuration.php

http://www.php.net/manual/en/function.ini-set.php


The sessions on PHP works with a Cookie type session, while on server-side the session information is constantly deleted.

For set the time life in php, you can use the function session_set_cookie_params, before the session_start:

session_set_cookie_params(3600,"/");
session_start();

For ex, 3600 seconds is one hour, for 2 hours 3600*2 = 7200.

But it is session cookie, the browser can expire it by itself, if you want to save large time sessions (like remember login), you need to save the data in the server and a standard cookie in the client side.

You can have a Table "Sessions":

  • session_id int
  • session_hash varchar(20)
  • session_data text

And validating a Cookie, you save the "session id" and the "hash" (for security) on client side, and you can save the session's data on the server side, ex:

On login:

setcookie('sessid', $sessionid, 604800);      // One week or seven days
setcookie('sesshash', $sessionhash, 604800);  // One week or seven days
// And save the session data:
saveSessionData($sessionid, $sessionhash, serialize($_SESSION)); // saveSessionData is your function

If the user return:

if (isset($_COOKIE['sessid'])) {
    if (valide_session($_COOKIE['sessid'], $_COOKIE['sesshash'])) {
        $_SESSION = unserialize(get_session_data($_COOKIE['sessid']));
    } else {
        // Dont validate the hash, possible session falsification
    }
}

Obviously, save all session/cookies calls, before sending data.


Prior to PHP 7, the session_start() function did not directly accept any configuration options. Now you can do it this way

<?php
// This sends a persistent cookie that lasts a day.
session_start([
    'cookie_lifetime' => 86400,
]);
?>

Reference: https://php.net/manual/en/function.session-start.php#example-5976