If you wish to list all cpanel accounts under specific re-seller , Then its very simple to list all cPanel users name via command line interface.
There is a file ‘/etc/trueuserowners‘ in your WHM server which has the record of all cPanel username and it’s owner’s name details.
List all users under a reseller account
Please follow the steps below to list out all cPanel accounts for a specific reseller account:
Step 1 : SSH to your server via putty as root user.
Step 2 : You can use the grep command to list all users’ name from /etc/trueuserowners file.
grep $Re-seller's-name /etc/trueuserowners | cut -d : -f 1