I really think you're pursuing an extinct animal. I did a little searching on the 'net, and the O'Reilly book is no longer being printed. Another book on CGI and C was dated 1996 - eons ago in hi-tech years. You can get a short on-line course (in C) from
http://www.papillion.ne.us/~sthomas/cgi_in_c.html The primary reason for using C or C++ is speed - when it comes to features and maintainability, there are much better alternatives thes days, such as
Java or PHP or Perl. The absolutely massive amount of overhead required to fork a new address space and process context is going to totally negate any speed
boost in the app itself. On the Microsoft platform when C++ is called for, they write DLLs - which are NOT CGIs and which only work with IIS. On the Apache server, you'd write an Apache module - which isn't a CGI either. And so on for other servers.
Few web apps are timing-critical. It's not practical in an environment where users come in in statistical clumps. Nor does the cost of hardware justify it - My servers are junk P-200's replaceable for perhaps $200 each and the only time you'll see an objectionable delay is if you call on a
JSP that has to be recompiled.
I wrote 2 or three CGI's in C or C++ (I forget) about 3 years ago. It was fun, but I wouldn't do it today except just to be able to day I'd done so.