Displaying HTML codes on web page

Q: How do I post html codes in full in a post to stop it changing into a clickable link?
A: http://www.plus2net.com/html_tutorial/tags-page.php

Here is a code generator which will convert your html tags to web page friendly display. Paste any html code here and copy the code printed above it. Paste that in your post editor. Publish post.

The end result:

<a href=http://www.plus2net.com>HTML Tutorials</a>

and not the usual click-able link: HTML Tutorials