While trying to install Oracle Java on an Ubuntu system, I used the command:
And Ubuntu responded with:
add-apt-repository: command not found
Well I've never seen that before. Usually add-apt-repository goes off without a hitch.
But apparently you have to install something else (sometimes) before you can use the add-apt-repository command.
apt-get install software-properties-common
Well then that fixed it and I was then able to run the add-apt-repository command.