https://en.wikipedia.org/wiki/Common_Gateway_Interface
In computing, Common Gateway Interface (CGI) offers a standard protocol for web servers to interface with executable programs running on a serverthat generate web pages dynamically. Such programs are known as CGI scripts or simply as CGIs; though usually written in a scripting language, they can be written in any programming language.
原文：http://www.cnblogs.com/yuanjiangw/p/5798687.html