# File lib/archive/extract.rb, line 24
    def initialize(filename, dir=Dir.pwd)
      unless File.exist?(filename)
        raise ArgumentError, "File '#{filename}' does not exist!"
      end

      unless File.directory?(dir)
        raise ArgumentError, "Directory '#{dir}' does not exist!"
      end

      @filename = filename
      @dir      = dir

      @extract_flags =
        LibArchive::ARCHIVE_EXTRACT_PERM |
        LibArchive::ARCHIVE_EXTRACT_TIME
    end