How to Use PHP Within Wordpress Posts

Installing Exec-PHP Plugin
1. Log into your WordPress blog through the Administration interface. From your dashboard, in the left menu, select 'Plugins,' then select 'Add New.'
2. Choose 'Term' from the drop-down menu. In the search box, type 'Exec-PHP' and click 'Search Plugins.' From the list of returning results, find 'Exec-PHP' and select 'Install Now.'

3. Select 'OK' when asked 'Are you sure you want to install this plugin?' The plugin will now begin installing, which may take a few moments to complete. When the message 'Successfully installed the plugin' appears, click the 'Activate Plugin' link below. The plugin is now ready for use.
Using PHP in posts
4. Click 'Posts' in the left menu. Now, you can click 'Add New' to start a new post using PHP, or you can click on any of the existing posts in the center column to add PHP code to an existing blog post.
5. Insert your desired PHP code within the content pane. Be sure to properly format your code. When you have finished, click the blue 'Publish' or 'Update' button at the top of the right column to save your work.
6. Visit the front-end of your blog and go to the post you have just created or edited. You should now see your PHP code in action within your post.