Check if an apt-get package is installed and then install it if it's not on Linux

Question

I\'m working on a Ubuntu system and currently this is what I\'m doing:

if ! which command > /dev/null; then
   echo -e \"Command not found! Install? (y/n)         


        

Answer 1

This seems to work pretty well.

$ sudo dpkg-query -l | grep  | wc -l

• It either returns 0 if not installed or some number > 0 if installed.