Creating a monkey patch to center align a string

center_align.rb

require 'tty-screen'

class String
  def center_align
    screen_width = TTY::Screen.width
    screen_center = screen_width / 2
    string_length = self.length             
    string_center = string_length/2 
    offset = screen_center - string_center 
    "#{sprintf("%#{offset}s" % self)}"
  end
end

puts "Hello World!".center_align

#=>                                    Hello World