A simple unzipper :)

unzip.rb

#rubygem: rubyzip
require 'zip/zip'

#Ex.: Unzip.from("my_file.zip").to("my_folder")
class Unzip
  def initialize(source)
    @source = source
  end
  def self.from(source)
    self.new(source)
  end
  def to(dest)
    Zip::ZipFile.open(@source) do |zip_file|
      zip_file.each do |f|
        f_path=File.join(dest, f.name)
        FileUtils.mkdir_p(File.dirname(f_path))
        zip_file.extract(f, f_path) unless File.exist?(f_path)
      end
    end
  end
end