Write CGI scripts in Pascal

Yves CANDAU
CERTES - Université Paris 12 - IUT
94000 CRETEIL

July 1997

Background

I wanted to add a touch of novelty to the server I maintain, with things like :

Registration Forms
hit counter

I downloaded a number of things from the net, including a library in Pascal for Windows, and various counter programs in C. Unfortunately, none of these seem to work with my NT 4.0 server. Don't ask me why ! I am sure I have made every reasonable effort.

To test what could be wrong, I started to write short CGI programs in Pascal, and found that I was doing all right; I also thought that it was easier to write for Turbo 7.0 (and thus generate Dos executables) than to try to figure out how Windows programs react. And so I thought it was easier to develop my own things in Pascal rather than try to debug C programs which where "about" suited to my needs.

Don't misunderstand me : Perl is a wonderful scripting language. It's just that I think that some things are easier with Pascal. As it is my hope that WWW applications will be more and more common on PC platforms, and thus increasingly opened to Pascal programmers, I want to share what I have done, for what it's worth, with my fellow Pascal adepts (and hope to get some return for it too).

As of today, I have two things to offer :

a Pascal unit, containing all that's necessary to parse the environment and the parameters (the QUERY_STRING) into meaningful Pascal variables
a unit for decoding/encoding GIF images (that was quite a bit of work) and a graphical counter program based on it (coming soon - I want to polish it a bit yet)

Installation

Note on downloading: on the Wanadoo server, text files will open in the Explorer Window, with a rather garbled look due to the lack of carriage return. Don't panic, simply save them on disk as text, with the correct extension (.pas or .htm according to the case).

Also, Wanadoo seems to hate Netscape. Use Microsoft Explorer: the files are really there.

download cgi.pas
compile it, using Turbo 7.0 or equivalent
to make a test, download ShowParam.pas and list.htm; put list.htm in your WWWroot directory and compile ShowParam.pas to your scripts directory. Use your browser to load list.htm (use a complete URL address : http://... DO NOT load as a local file)
To check a more complex application, you can download a program which processes the parameters obtained through this form.

You can download the whole bunch, including source and exe files, by going directly to my ftp directory

Learning more about CGI scripts

Learning more about forms

updated October 07, 2000