Validating input

…In this movie, we'll learn how to validate input with PHP.…After configuration, this should be your next step in securing any site.…It's not about skilled hackers trying to get in through some mysterious back door.…This is about information coming in through the front…door, through well-known visible pathways into your web application.…You can think of it like the security screening at the airport.…And it's better to stop problems right there…at the gate before they can get inside.…To recognize bad data, we first need to…give some thought to what good data looks like.…

And this is going to vary for every project that you work on.…For example, image that we're creating new user accounts.…On one project, all user names might be limited to a…maximum of 10 characters and use only lower case letters and numbers.…On another project, user names might be allowed to be any valid email address.…And on another project, you might allow…capital letters, dashes and underscores, but not numbers.…You'll need to closely examine the needs of your project…