Switch to admin theme based on path using hook_init() or template.php in Drupal 7

Question

I'm running a site that uses a separate admin theme. I'd like to include a couple additional pages that use the admin stylesheets. How can I apply the theme selectively to these pages. I'd rather do this in hook_init() or template.php. I don't want to add any more contrib modules to the site at this point. Thanks for any illumination.

Answer 1

The Administration theme module will do it, but given you'd like to do it yourself, it does cast some light on that path by suggesting the hook_admin_theme_check() and hook_admin_theme_info() hooks.