Troubleshooters.Com Presents

July 1999 Troubleshooting Professional Magazine: Troubleshooting CGI

Copyright (C) 1999 by Steve Litt. All rights reserved. Materials from guest authors copyrighted by them and licensed for perpetual use to Troubleshooting Professional Magazine. All rights reserved to the copyright holder, except for items specifically marked otherwise (certain free software source code, GNU/GPL, etc.). All material herein provided "As-Is". User assumes all risk and responsibility for any outcome.

<-- | Contents | CGI Review-->

Editors Desk

By Steve Litt

Common Gateway Interface (CGI) programming has gotten an ill-deserved reputation as difficult and slow to develop. It actually develops very fast. But debugging slows the project to a crawl. It doesn't have to be that way.

The problem has several causes:

Your program writes code which must be interpreted yet again.
The UID you develop under is not the UID used to invoke it, so permissions and modes get in the way.
It's a black box. Unless you have telnet there are no test points. Under error conditions the browser simply gives an unhelpful single line message.

Troubleshooting CGI can seem like trying to fix a radio without using a voltmeter.

But it doesn't have to be that way. You can follow the lead of generations of Troubleshooters making their own tools from coathangers and tape. I recently saw an auto mechanic identify the source of a strange noise by placing a long screwdriver's handle to his ear, placing the blade on various parts of the engine and components, and determining where the noise was loudest (this is dangerous -- I don't recommend it).

In the case of CGI, your tools are made with shellscript and Perl code. And once you've made them, you'll see inside your web providers server, you'll see inside your CGI program, you'll see the communication between your CGI and the browser, you'll even see the stderr error messages.

Best Content of the Year

But the best comes last. Prolific Troubleshooting Professional Magazine guest author Marc-Henri Poget presents a diamond in the rough with the potential to add significant new knowledge and process to System Independent Troubleshooting. In this article Marc begins to explain authoring processes we all can use in creating Era 4 Troubleshooting System, using CGI Troubleshooting for his examples. Like all good content, it leaves the reader with more questions than he started with. Hard core Troubleshooters will doubtlessly want to add insight to the discussion Marc starts here. Gentlemen, start your engines!

So kick back, relax, and enjoy this issue of Troubleshooting Professional. Learn the tools and techniques that allow some CGI specialists to achieve quadruple the average productivity. And remember, if you're a Troubleshooter,
Technologist, or free software user, this is your magazine. Enjoy!

Steve Litt can be reached at Steve Litt's email address.

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