# Cat A File With Line Numbers You can quickly view a file using `cat` ``` $ cat Gemfile source 'https://rubygems.org' # Bundle edge Rails instead: gem 'rails', github: 'rails/rails' gem 'rails', '4.2.0' # Use postgresql as the database for Active Record gem 'pg' ``` With the `-n` flag you can view that file with line numbers ``` $ cat -n Gemfile 1 source 'https://rubygems.org' 2 3 4 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails' 5 gem 'rails', '4.2.0' 6 # Use postgresql as the database for Active Record 7 gem 'pg' ```