Debian Ubuntu apt install stop daemon questions/accept the default action without prompting
This can be a real pain when automating things and you do an apt install and some packages ask a lot of questions.
Make sure you set this variable when running:
DEBIAN_FRONTEND=noninteractive
Remember as well that if chrooting you will want to run like this:
DEBIAN_FRONTEND=noninteractive apt install -y yourpackagename
........
Debian, Mint Ubuntu how to remove package and associated config files
If you want to start fresh a lot of people falsely assume that an apt remove and then reinstall or apt --reinstall install package will start you off fresh. To be sure and remove all associated config files do the below with the example of ssh server (don't remove it though if you actually use it!)
The key below is using the --purge flag or apt-get purge proftpd (eg sudo apt --purge remove packagename)
apt purge proftpd; apt install proftpd........
Linux Mint/Ubuntu/Debian apt how to downgrade a package
First of all check to see which version if any you have available for a downgrade:
apt-cache showpkg packagename
Click here to see what versions/older ones are available.
Downgrade/Install old package:
apt-get install package=version
Example........
Ubuntu Linux Mint How To Exclude Stop Package from being Upgraded or Installed
In Debian/Ubuntu this is called "holding".
To hold/exclude a package from being installed or upgraded:
sudo apt-mark hold packagename
To allow the upgrade/installation unhold:
sudo apt-mark unhold packagename........