If you're like most people on the newsgroup, you've presented us with the clasiquísimo CGI problem: ``it doesn't work'', without providing us sufficient background to divine what the real problem is. This is infuriating, because is makes you come off like some drooling idiot begging for free consulting help without having done any investigation on your own part. This drives people away who could otherwise help you and impoverishes the Net by exacerbating the already annoyingly low signal-to-noise ratio

This is an introduction to writing CGI programs in the C language. The reader is assumed to know the basics of C as well how to write simple forms in HTML and to be able to install CGI scripts on a Web server. The principles are illustrated with very simple examples

CGI is simply an interface between HTML forms and server-side scripts. It is not the only possibility--see the excellent tutorial How the web works: HTTP and CGI explained by Lars Marius Garshol for both an introduction to the concepts of CGI and notes on other possibilities. But CGI is widely used and useable.If someone suggests using JavaScript as an alternative to CGI, ask him to read my JavaScript and HTML: possibilities and caveats. Briefly, JavaScript is inherently unreliable at least if not "backed up" with server-side scripting.

Freeware CGI Scripts are available for download all over the Web. But how many of them are really secure? When you download a cgi script do you check all the logic to make sure it is secure? Do you read through each line of code and anticipate all the ramifications? Most of the time the answer is "no". After all, the whole point of downloading software is to get it and run it for free WITHOUT having to do a lot of work.

I'm writing this to tell you that there isn't any free lunch out there. The more complicated a CGI script is, the more likely you will want to find someone else who has already programmed it and avoid doing the work yourself.

Need a CGI program customized to your unique requirements? We have a team of programmers who may be able to help you. Our standard programming rates are anywhere between $35-50 per man-hour, depending on the complexity of your specifications. We try our best to cater to all types of requirements, hence, nothing is too simple or too complex for us.

The Common Gateway Interface, or CGI, permits interactivity between a client and a host operating system through the World Wide Web via the Hyper Text Transfer Protocol (HTTP). It's a standard for external gateway programs to interface with information servers, such as HTTP or Web servers. A plain HTML document that the Web server delivers is static, which means it doesn't change. A CGI program, on the other hand, is executed in real-time, so that it can output dynamic information - perhaps a weather reading, or the latest results from a database query. CGI allows someone visiting your Web site to run a program on your machine that performs a specified task.