I wanted to prove myself, that writing WordPress plugins isn’t very hard task. Or, actually, that this can be really, really easy. So I came with this example. This is as simple as possible plugin example. It currently does nothing else except for locking entire front-end of your site for not registered users.
Here is my fantastic code:
* Plugin Name: Guest Lock
* Description: Makes your blog accessible only to logged in users. Displays message to all others.
* Version: 1.0
* Author: Trejder
echo(‘No way, man!’);
Everything, what this plugin does can be achieved using build-in WordPress solution, so you should consider this plugin as a piece of fun or base template rather than something usable.