formatmp3s.rb

require "id3tag"

unless ARGV[0]
  raise "No mp3 directory given!"
end
dir = ARGV[0]
unless dir.end_with? "/" then dir += "/" end

mp3s = Dir.glob(dir + "*.mp3")

mp3s.each do |file|
  if file.split("/").last.match(/\d+\. .* - .*\.mp3/) then next end
  ID3Tag.read(File.open(file, "rb")) do |tag|
    puts "#{tag.track_nr}. #{tag.title} - #{tag.artist}"
  end
end