This folder contains a copy of the program "env.cgi" . However, "get.html" submits the form data to 

http://www.cknuckles.com/cgi/env.cgi 

on the server. This program returns information on all of the environment variables created for the transaction on our LINUX/APACHE server.  The program does not check the user name and password.

Also note that Figure 18.5 in the book uses a slimmed-down version of "env.cgi", which returns information on only 6 of the environment variables.
