This utility script will take that guesswork away. Keep it on your hard drive and install it on every single server you work on. Then all you have to do is call it in your browser and you will get a report of all the Environment Variables being spit out by your server.

In addition, this script shows a few tricks as to how you can use these Environment Variables to make your scripts more portable and easy to use.

I will be expanding on this one in the future so if you have any ideas or neat-o tricks for using Environment Variables, then let me know and maybe I'll include them in the next version.