Require login on non-WP page

Here’s a fairly simple method (stick at the top of any non-WordPress PHP document):

<?php
include('wp-blog-header.php');

global $user_identity;
if(!$user_identity)
die('Sorry, you must be <a href="'. get_bloginfo('home') . '/wp-login.php?redirect_to=' . $_SERVER['PHP_SELF'] . '">logged in</a> to view this page.');
?>

Modify the path in the include, if necessary, to the correct location of wp-blog-header.php.

Thanks!

Hrmm…. I tried Kafkaesqui’s suggestion and it didn’t work. Even when I’m logged in, the content doesn’t show. I guess I should mention I need a code that will work on a DIFFERENT domain.

I tried using…

<?php
include('[ABSOLUTE URL]/wp-blog-header.php');

global $user_identity;
if(!$user_identity)
die('Sorry, you must be <a href="[ABSOLUTE URL]/wp-login.php">logged in</a> to view this page.');
?>

If anyone knows how to do this, I’d REALLY appreciate it. Thanks.

I need a code that will work on a DIFFERENT domain.

That’s a HUGE difference. Others may correct me, but I don’t think there is something like that.
Imagine, it would be like: you have to be logged in to this forum to see my site (which is on a different domain).

No correction from me.

So it can’t be done, huh? Poo. =(
I was hoping there’d be something that just checks if a WP cookie for my domain is present or not, and if it isn’t then it gives a message to login. I guess I’ll have to think of something else.

Thanks for your help everyone.