$ sudo apt-get update
$ sudo apt-get install libcommandline-ruby 

libcommandline-ruby is installed in your system.

Make ensure the libcommandline-ruby package were installed using the commands given below,

$ sudo dpkg-query -l | grep libcommandline-ruby *

You will get with libcommandline-ruby package name, version, architecture and description in a table

libcommandline-ruby package basic information: