What Is CGI?

If you want to deploy your COBOL applications on the Web without any configuring of the user machine, you can develop a Web interface to your application and write a CGI program on the server. CGI stands for Common Gateway Interface. It is an Internet standard that defines how a Web server communicates with an external program.

Using CGI, your application becomes immediately available to any user with a Web browser or mobile device. The end user does not require any special runtime or plug-in to interface with your application, because the CGI script handles the communication for them.

The CGI program (also known as the CGI script) can be written in any language, including COBOL. By writing it in the ACUCOBOL-GTĀ® Development System, you can take advantage of your COBOL programming experience, as well as many other benefits.

This option gives the most flexibility and platform independence, but it requires the development of a new user interface and a modest amount of COBOL programming.

Why Write CGI Programs in ACUCOBOL-GT?

ACUCOBOL-GT has features designed to simplify CGI programming. For instance, using familiar ACCEPT and DISPLAY syntax, you can accept CGI input data and write HTML, WML, or XML output forms. It also has configuration variables that address special formatting and storage issues in this environment.

By writing CGI programs in a language you already know, you have to learn only what the Web server expects, and how it formats messages that it passes back and forth across the network.

Another advantage is that your CGI program is compiled when it is written in ACUCOBOL-GT. This not only speeds up processing, but it reduces the size of the finished product, and secures your program from anyone who might try to acquire and modify it. Your CGI program is not sent across the Internet, only the data (if any) and response (if any). Users won't know if your CGI program is written in COBOL or another language. They see only the results.

Sample Scenario

Your inventory program allows customers to place orders online. They fill out an HTML form on your Web site, which provides input to a CGI program (written in COBOL). The CGI program updates inventory information in your database to reflect the customer order, and then returns a confirmation notice in HTML format to the customer's browser. Alternatively, the notice may be sent in WML format to the customer's mobile phone or other wireless device.