Thoroughly understand the operating principles of cgi

1.CGI The earliest web servers only processed static html files. With the continuous development of technology, websites become more and more complex, and then dynamic websites appear, but the service cannot directly run dynamic language files such as php and asp, and then cgi appears, which is just an interface protocol . The full name of CGI (Common Gateway Interface) is “Common Gateway Interface“, which is passed between the Web server and external applications (CGI programs). Information interface standard. Through the CGI interface, the Web server can obtain the information submitted by the client, and transfer it to the CGI program on the server side for processing, and finally return the result to the client. CGI can be written in any language, as long as the language has standard input, output, and environment variables. Such as php, perl, tcl, etc. The web server receives the request, and then forks a new process according to the content. This process will return the processed data to the web server, and finally the web server sends the content to the user. The fork process just now follows After exiting, if the user also requests to change the dynamic script next time, the web…