id3dump

#!/usr/bin/ruby

require 'rubygems'
require 'id3lib'

def usage()
  STDERR.puts "Usage: id3dump <mp3-file>"
  exit 1
end

if ARGV.length != 1 then
  usage
end
file = ARGV[0]
if !File.readable? ARGV[0] then
  STDERR.puts "Error: Cannot read the file you provided. [#{file}]"
  usage
end

# Note: avoids printing comment tags. The fear-the-boom-and-bust.mp3 comment is just so big!

v1_tags = [:title, :artist, :album, :year, :composer, :genre, :track]
v1_max_len = v1_tags.map {|i| i.to_s.length}.max
tags = ID3Lib::Tag.new(file)
puts "some common v1 tags {"
v1_tags.each { |tag|
  printf "  %-#{v1_max_len + 1}s \"%s\"\n", tag.to_s + ":", tags.send(tag)
}
puts "}"

puts "v2 tags {"
tags.select {|frame| frame[:id] != :COMM}.each do |frame|
  puts "  #{frame[:id]}: \"#{frame[:text]}\""
end
puts "}"