If you want to hide your wordpress website, so that, only logged in users may access it. So, here’s the quick fix.
append following code into your wp-blog-header.php file right below wp();
//****************************************************//
/////////////////////////// Require login to view website
get_currentuserinfo();
global $user_ID;
if ($user_ID == '')
{
header('Location: wp-login.php');
}
////////////////////////// Require login to view website
//*****************************************************//
Thats it. Simple enough ?