FAQ: Frequently Asked Questions about CGI Programming

• Introduction
• Table of Contents
• SECTION 0 - PREAMBLE
• 0.1 Changes
• 0.2 Notice and Disclaimer
• 0.3 Where to get this document
• 0.4 How to contribute to this document?
• 0.5 Can I email the author my questions?
• 0.6 What's up with posting to comp.infosystems.www.authoring.cgi?
• 0.7 Credits
• SECTION 1 - BASIC QUESTIONS
• 1.1 What is CGI?
• 1.2 Is it a script or a program?
• 1.3 When do I need to use CGI?
• 1.4 Should I use CGI or JAVA?
• 1.5 Should I use CGI or SSI?
• 1.6 Should I use CGI or an API?
• 1.7 What do I absolutely need to know?
• 1.8 Does CGI create new security risks?
• 1.9 Do I need to be on Unix?
• 1.10 Do I have to use Perl?
• 1.11 Do I have to put it in cgi-bin?
• 1.12 Do I have to call it *.cgi? *.pl?
• 1.13 What is CGIWrap, and how does it affect my program?
• SECTION 2 - HTTP HEADERS AND NPH SCRIPTS
• 2.1 What is HTTP (HyperText Transfer Protocol)?
• 2.2 What HTTP request headers can I use?
• 2.3 What Environment variables are available to my application?
• 2.4 What HTTP response headers do I need to know about?
• 2.5 What is NPH?
• 2.6 Must/should/can I write nph scripts?
• 2.7 Do I have to call it nph-*
• 2.8 What is the difference between GET and POST?
• SECTION 3 - TECHNIQUES: "HOW DO I..."
• 3.1 Can I get information about who is visiting?
• 3.2 Can I get the email of visitors?
• 3.3 "But I saw some.kool.site display my email address..."
• 3.4 Can I get browser details and return different pages?
• 3.5 Can I trace where a user has come from/is going to?
• 3.6 Can I launch a long process and return a page before it's finished?
• 3.7 Can I launch a long process which the user interacts with?
• 3.8 Can I password-protect my pages?
• 3.9 Can I do HTTP authentication using CGI?
• 3.10 Can I identify users/sessions without password protection?
• 3.11 Can I redirect users to another page?
• 3.12 Can I run a CGI script without returning a new page to the browser?
• 3.13 Can I write output to a different Netscape frame?
• 3.14 Can I write output to several frames at once?
• 3.15 Can I use a CGI script to generate both text and inline images?
• 3.16 How can I use Caches to make CGI scripts faster and more Net-friendly?
• SECTION 4 - APPLICATIONS: IS THERE AN EXISTING SCRIPT TO ...
• 4.1 Where to look for free scripts for my application?
• 4.2 Discussion group/bulletin board
• 4.3 CSCW/Groupware
• 4.4 Database
• SECTION 5 - TROUBLESHOOTING A CGI APPLICATION
• 5.1 Are there some interactive debugging tools and services available?
• 5.2 I'm having trouble with my headers. What can I do?
• SECTION 6 - FURTHER READING
• 6.1 Other FAQs/collections (including online book)
• 6.2 Reference Pages
• INDEX