<!-- Collection of code snippets by Arne Vajhøj -->
<!-- posted to eksperten.dk, usenet and other places (2002-now) -->
<?php

// sligthly modified version of code from http://www.php.net/manual/en/function.session-set-save-handler.php

$hook = '';
$sess_save_path = session_save_path();

function special_session_decode($session_string){
    $current_session = session_encode();
    foreach ($_SESSION as $key => $value){
        unset($_SESSION[$key]);
    }
    session_decode($session_string);
    $restored_session = $_SESSION;
    foreach ($_SESSION as $key => $value){
        unset($_SESSION[$key]);
    }
    session_decode($current_session);
    return $restored_session;
}

function open($save_path, $session_name) {
    global $sess_save_path;
    $sess_save_path = $save_path;
    return true;
}

function close() {
    return true;
}

function read($id) {
    global $sess_save_path;
    $sess_file = "$sess_save_path/sess_$id";
    return (string) @file_get_contents($sess_file);
}

function write($id, $sess_data) {
    global $sess_save_path;
    $sess_file = "$sess_save_path/sess_$id";
    if ($fp = @fopen($sess_file, "w")) {
        $return = @fwrite($fp, $sess_data);
        fclose($fp);
        return $return;
    } else {
        return false;
    }
}

function destroy($id) {
    global $hook;
    $hook(special_session_decode(read($id)));
    global $sess_save_path;
    $sess_file = "$sess_save_path/sess_$id";
    return @unlink($sess_file);
}

function gc($maxlifetime) {
    global $sess_save_path;
    foreach (glob("$sess_save_path/sess_*") as $filename) {
        global $hook;
        $hook(special_session_decode(@file_get_contents($filename)));
        if (filemtime($filename) + $maxlifetime < time()) {
            @unlink($filename);
        }
    }
    return true;
}

function set_session_destroy_hook($callback) {
    global $hook;
    $hook = $callback;
    session_set_save_handler('open', 'close', 'read', 'write', 'destroy', 'gc');
}
?>