How to get WordPress Adminmenu items?

Menu and submenu data is accessible through the $menu and $submenu globals:

add_action( 'admin_notices', 'so19890599_print_menus' );
function so19890599_print_menus()
{
    global $menu, $submenu;

    echo '<pre>'; print_r( $menu ); echo '</pre>';
    echo '<pre>'; print_r( $submenu ); echo '</pre>';
}