dingo@dev:~$ sudo apt-get install firefox
[sudo] password for dingo:
Reading package lists... Done
Building dependency tree
Reading state information... Done
firefox is already the newest version.
0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
dingo@dev:~$ firefox
The program 'firefox' is currently not installed. You can install it by typing:
sudo apt-get install firefox
dingo@dev:~$