设置php Session超时

用户登陆时设置
$_SESSION['id'] = $userid;
$_SESSION['session_time']=time();

以下这段是每个页面都会include/require的内容:

if (!isset($_SESSION)) {    session_start();}if (!isset($_SESSION['id'])) {    header ("Location: " . WEB_ROOT . "index.php");    return ; }$timeout=1200; //超时时间,单位:秒,这里设为20分钟.$now = time();if(($now-$_SESSION['session_time'])>$timeout){//超时了.unset($_SESSION['id']);header ("Location: " . WEB_ROOT . "index.php");return;}else{//还没超时.$_SESSION['session_time']=$now;}

 

注销session还有一些代码

    $_SESSION = array();    if (isset($_COOKIE[session_name()])) {        setcookie(session_name(), '', time()-42000, '/');    }    session_destroy();