Filtering User Input in PHP

Never trust input. I have said this many times before, and am always cognizant of this phrase when I am developing new websites or web applications. Always assume that someone is going to try to exploit your program - be it with malicious intentions or not.

With this article, I want to shed some light on some of the ways to protect the security, quality and integrity of you web applications written in PHP and MySQL. There is always going to be rotten people out there that want to take advantage of a poorly secured or filtered program - think of it like someone breaking into a house that has no locks on the front door.