Working with Hex in Ruby

gistfile1.rb

#!/usr/bin/env ruby

start = ARGV[0].to_s.hex
len = ARGV[0].to_s.length

count = 0

until count == ARGV[1].to_i
	puts "%0#{len.to_s}x" % start
	zeros = ""
	[0..len-1].each do
		zeros += "0"
	end
	zeros += "1"
	start -= zeros.hex
	count += 1
end