Common Gateway Interface (CGI) is method of extending web server functionality by executing scripts on a Web server.  A common use of CGI is in form processing, where the Web browser sends form data to a CGI script on the server, the script retrieve the data from a database, and sends back the results as a Web page.  You can think WordPress is form of CGI with hundred of complex CGI scripts.

You can run cgi scripts on su.domains using perl, php, unix-shell scripts.  All you need is to upload your scripts to the public_html/cgi-bin folder using cPanel’s FileManager.  Please see the “Accessing your files though the File Manager” article for more detail.

Here is a sample of the hello worlds in perl cgi.

#!/usr/bin/perl
## example of a cgi script called helloworld.pl
use strict;
use warnings;

print "Content-type: text/html\n\n";
print "Hello World!";

After uploaded the above script to your public_html/cgi-bin folder, you can goto https://yourdomain.su.domains/cgi-bin/helloworld.pl to see it in action.

While su.domains platform support cgi as well as static html for your website, we encourage you to use content manager systems (CMS) such as WordPress, Drupal, Joomla, etc.,. These CMS system is much more easy to maintain and manage for years to come.