In This Chapter
Considering what WordPress plugins are — add-on programs that provide limitless possibilities to extend WordPress — and considering how many plugins there are — over 10,000 in the WordPress Plugin Directory — likely, you can find a plugin that does what you want. However, what if that plugin meets only part of your requirements? What if it's a good starting point but requires some work to get it to do what you need? Thankfully, if it's in the WordPress Plugin Directory, then it's licensed in a way that you can alter the code for your own purposes. You can even redistribute the changed plugin as long as you comply with the GPLv2 license.
So where do you start? How do you go about taking someone else's plugin and modifying it for your own purposes? In this chapter, we explore basic plugin code, describe how to tell what the code does, and explain how to find and fix problems in that code.