Look here when Chapter 6 of the book mentions something extra to be found on the web site.
Here is the program
which prints out a table showing the entire %ENV
hash (from the Apache server).
Here is the final decoding routine
as shown in Section 6.10 of the book. Use this as a template for new programs which need to URL-decode incoming data. Note that this file is also supplied for download with the source code archives.
Manual Query String:
The links below send data to the randomlinks.cgi
program manually by attaching it as query strings to the URLs in the links as shown in Figure 6.6.
the empty string as data.
the integer 1000 as data.
the integer 4 as data.