如果你去www.example.com/private_page

使用CodeIgniter(在私人页面上)

// if user is not logged in...
$_SESSION['redirect'] = $this->uri->segment(1);
redirect('login');

在登录页面上

// successfully logged in..
if (isset($_SESSION['redirect'])) {
    redirect($_SESSION['redirect']);
} else {
    // redirect to default page
}