Shows all valid hosts on a Windows machine

show-hosts.rb

# This is where it all starts and ends
begin
  # It saves all the lines of the file inside
  # the 'contents' variable.
  # Note that we use '/' as the path separator
  # (and not '\')
  contents = File.read("C:/Windows/system32/drivers/etc/hosts")
  
  # We're going through each line of 'contents',
  # assigning one at a time to the 'line' variable.
  contents.each_line do |line|
  
    # For each 'line', we'll show it if it's
	# not a comment.
	puts line if not line.match(/^\s*#/)
	
	# 'puts' shows stuff on the screen.
	# 'match' compares the string to a Regular Expression.
	#
	# Idk if you know what those are, but think of
	# them as indicators of what should be on a string.
	# 
	# That '/^\s*#/' is trying to see if the string 'line'
	# * Begins the line (^) with zero spaces or more (\s*)
	# * Has a '#' after them (#)
  end
  
  # And that's it!
  exit
end