So.... What's CGI Then?

• The Common Gateway Interface.
• Not a language, but a protocol for web programming.
• The Perl scripts we write will be CGI scripts, though Perl can be used for other purposes.
• Not all CGI scripts are Perl scripts.
• Basically, CGI says:
• Referencing a CGI script with a URL is executing the script.
• Nearly all web programming is performed through some type of CGI script.
• The environment variables are treated as input to the program.
• If formed properly, the outputs of the program compose the HTML page returned by running the script.
• So....
• You can manipulate input variables with Perl.  Form data, browser, etc.
• You can generate dynamic HTML with Perl.
• CGI is a standard, so most ISPs support it.