How to protect PDF files using PHP

This tutorial explains how to safely hide away PDF files from public access using htaccess, but then having a PHP file run its own authorization to allow access to the file without the Network Password dialog box. The PDF file will be displayed in the browser (if the user has acrobat reader) or promoted to download the pdf file if the user doesn't have acrobat reader. This is perfect for when you want to restrict PDF files to authorized eyes only. This simple to use tutorial will have you up and running in a few minutes, one page of info with full source code, and working examples.