Turn a number to bytes in Ruby

number_to_bytes.rb

class Numeric
  def to_bytes
    f = self
    1.upto((Math.log2(self)/8).ceil).collect do
      f, c = f.divmod 256; c
    end.reverse
  end
end

if __FILE__ == $PROGRAM_NAME and ARGV.length > 0
  p ARGV[0].hex.to_bytes.pack("c*")
end

# ruby bytes_demo.rb 0x7075626c696320646f6d61696e #=> "public domain"