Rename mp3 files for my Toyota radio to maintain song order. Copy this file to folder of mp3 files for an album and run it.

rename_for_car

#!/usr/bin/env ruby
# coding: utf-8

require 'rubygems'
require "mp3info"

dir = File.expand_path(File.dirname(__FILE__))
Dir["#{dir}/*mp3"].each do |filename|
  Mp3Info.open(filename) do |mp3|
    disk_num = mp3.tag2["disc_number"]
    track_num = "%02d" % mp3.tag2["TRCK"].split("/")[0].to_i
    new_filename = "#{disk_num}_#{track_num}_#{File.basename(filename)}"
    File.rename filename,"#{dir}/#{new_filename}"
    puts "renamed #{File.basename(filename)} to #{new_filename}"
  end
end