debian/ubuntu: Prevent UI prompting in command-line apt-get

Solution 1:

This will reconfigure your package with default parameters:

DEBIAN_FRONTEND=noninteractive dpkg-reconfigure [package name]

This will display parameters you set when installing a package:

debconf-show [package name]

This will output parameters you set when installing a package, formatted to be loaded in debconf-set-selections:

debconf-get-selections | grep '^[package name]'

To my knowledge, you can't display parameters for packages you didn't install; and you can't display default parameters without first re-configuring your package using the noninteractive option. You may want to use containers for testing purpose.