Several units of the System, Help!

Hi, I have a little doubt with a code that I’m doing, and that is what I
need is to open a file with “File”, with the exact route, but saying
that I look at all the units of the system, or the ‘A’ to ‘Z’. How could
I do?, Here you get the code.

require ‘ftools’
ip=ARGV[0]
dns=ARGV[1]
if !ARGV[0] or !ARGV[1]
puts “Example use => “./phar 72.14.221.104 google.es””
end
host=File.open(‘C:/Windows/System32/drivers/etc/hosts’ , ‘a+’)
host.print("#{ip}\s\s\s\s", “#{dns}\n”)

This is: " …===> C: <===/Windows/System32/… "