We all know how to list subdomains/addon domains under an account after logging to cPanel of that user. But it is a bit time consuming to log in and browse between options. There is a better and faster way to list all addon/parked and subdomains of a cPanel user provided you have SSH root access to the server.
In a cPanel server, all user configurations are stored/saved in /var/cpanel/userdata/ inside a directory with the cPanel username of the user. ie for the cPanel user user123, the userdata directory will be ‘/var/cpanel/userdata/user123’ Now inside this directory, there will be a file ‘main’ which lists all there you can see all the domain associated with that particular cPanel account.
When you check, be sure to replace ‘user123’ with the username of the cPanel account in question.