Writing Apache Modules with Perl and C

Chapter 1. Server-Side Programming with Apache

Before the World Wide Web appeared, client/server network programming was a drag. Application developers had to develop the communications protocol, write the low-level network code to reliably transmit and receive messages, create a user interface at the client side of the connection, and write a server to listen for incoming requests, service them properly, and transmit the results back to the client. Even simple client/server applications were many thousand lines of code, the development pace was slow, and programmers worked in C.

When the web appeared in the early '90s, all that changed. The web provided a simple but versatile communications protocol standard, a universal network client, and a set of reliable and well-written network servers. In addition, the early servers provided developers with a server extension protocol called the Common Gateway Interface (CGI). Using CGI, a programmer could get a simple client/server application up and running in 10 lines of code instead of thousands. Instead of being limited to C or another "systems language," CGI allowed programmers to use whatever development environment they felt comfortable with, whether that be the command shell, Perl, Python, REXX, Visual Basic, or a traditional compiled language. Suddenly client/server programming was transformed from a chore into a breeze. The number of client/server applications increased 100-fold over a period of months, and a new breed of software ...