Summary of zipfile by mime type

zip_contents_summary.rb

require 'zip'
require 'mimemagic'

zipfilename = ARGV[0]

class MimeStats
 attr_accessor :type, :size, :csize, :count
 def initialize(type, size = 0, csize = 0)
   @type = type
   @size = size
   @csize = csize
   @count = 0
 end

 def add(size, csize)
    @size += size
    @csize += csize
    @count += 1
 end

end

mimetypes = Zip::File.open(zipfilename).each_with_object(Hash.new{|h, k| h[k] = MimeStats.new(k)}) do |e, mt|
  next if e.directory?
  guess =  MimeMagic.by_path(e.name)
  type = if guess.nil?
           filename_components = e.name.split('/').last.split('.')
           filename_components.size > 1 ? '.' + filename_components.last : "unknown"
         else
           guess.type
         end
  mt[type].add(e.size, e.compressed_size)
end

puts "\n" + zipfilename
puts "\n%-40s %-3s %10s %10s" % %w[Type Cnt Size CSize]
mimetypes.keys.sort{|a,b| mimetypes[b].csize <=> mimetypes[a].csize}.each do |type|
  stats = mimetypes[type]
  puts "%-40s %3d %9.0fk %9.0fk" % [type, stats.count, stats.size / 1024.0, stats.csize / 1024.0]
end