tag.rb

require 'kconv'
def title_of(path)
  case path
  when /\d\d-(.*)\.mp3/, /\d\d_(.*)\.mp3/, /\d\d(.*)\.mp3/
    $1.tosjis
  else
    raise path
  end
end
def tag!(files, is_dry, album=nil)
  files.each_with_index do |path, i|
    extra_option = "--album '#{album}'" if album
    #"--artist 'capsule' --album 'Fruits Clipper'"
    cmd = "id3v2 --song '#{title_of(path)}' --track #{i+1} #{extra_option} '#{path}'"
    puts cmd
    system cmd unless is_dry
  end
end

if ARGV.size==0
  puts "usage: #$0 dir"
  puts "options: -d : dry-run"
else
  files = Dir["#{ARGV[0]}/*.mp3"]
  tag!(files, ARGV[1] == "-d", File.basename(ARGV[0]))
end