Basic Questions

What is CGI?
The Common Gateway Interface

Is it a script or a program?
The distinction is semantic

When do I need to use CGI?
There are innumerable caveats to this answer

Should I use CGI or JAVA?
answer to this non-question hopes to try and reduce the noise level of the recurrent "CGI vs JAVA" threads

Should I use CGI or SSI or ... { PHP/ASP/... }
CGI and SSI (Server-Side Includes) are often interchangable

Should I use CGI or an API?
APIs are proprietary programming interfaces supported by particular platforms

So what are in a nutshell the options for webserver programming?
Too many to enumerate - but I'll try and summarise

What do I absolutely need to know?
If you're already a programmer, CGI is extremely straightforward

Does CGI create new security risks?
There is a lot you can do to minimise these

Do I need to be on Unix?
The Web, along with the Internet itself, C, Perl

Do I have to use Perl?
No - you can use any programming language you please

What languages should I know/use?
It isn't really that important

Do I have to put it in cgi-bin?
It depends on your server installation

Do I have to call it *.cgi? *.pl?
It depends on your server installation

What is the "CGI Overhead", and should I be worried about it?
The CGI Overhead is a consequence of HTTP being a stateless protocol

What do I need to know about file permissions and "chmod"?
Unix systems are designed for multiple users

What is CGIWrap, and how does it affect my program?
CGIWrap is a gateway program that allows general users to use CGI scripts

How do I decode the data in my Form?
The normal format for data in HTTP requests is URLencoded