Khi World Wide Web được sinh ra, chỉ có một web server và một web khách hàng. Các máy chủ web httpd được phát triển bởi Trung tâm d'Etudes et de recherche Nucléaires (CERN) tại Geneva, Thụy Sĩ. httpd đã trở thành tên chung chung của nhị phân thực thi của máy chủ web nhiều. Khi CERN ngừng tài trợ phát triển của httpd, nó đã được thực hiện trên của nhóm phát triển phần mềm của Trung tâm quốc gia ứng dụng siêu máy tính (NCSA). Các NCSA cũng sản xuất Mosaic, trình duyệt web đầu tiên, mà các nhà phát triển sau này đã. | Page 3 Thursday November 18 2004 12 34 PM CHAPTER 1 Introducing CGI and mod_perl This chapter provides the foundations on which the rest of the book builds. In this chapter we give you A history of CGI and the HTTP protocol. An explanation of the Apache Unix model which is crucial to understanding how mod_perl works. An overall picture of mod_perl and its development. An overview of the difference between the Apache C API the Apache Perl API . the mod_perl API and CGI compatibility. We will also introduce the Apache Registry and Apache PerlRun modules. An introduction to the mod_perl API and handlers. A Brief History of CGI When the World Wide Web was born there was only one web server and one web client. The httpd web server was developed by the Centre d Etudes et de Recherche Nucléaires CERN in Geneva Switzerland. httpd has since become the generic name of the binary executable of many web servers. When CERN stopped funding the development of httpd it was taken over by the Software Development Group of the National Center for Supercomputing Applications NCSA . The NCSA also produced Mosaic the first web browser whose developers later went on to write the Netscape client. Mosaic could fetch and view static documents and images served by the httpd server. This provided a far better means of disseminating information to large numbers of people than sending each person an email. However the glut of online resources soon made search engines necessary which meant that users needed to be able to A static document is one that exists in a constant state such as a text file that doesn t change. 3 Page 4 Thursday November 18 2004 12 34 PM submit data such as a search string and servers needed to process that data and return appropriate content. Search engines were first implemented by extending the web server modifying its source code directly. Rewriting the source was not very practical however so the NCSA developed the Common Gateway
