Work with native TAR files on Ruby

tar_handler.rb

# based on https://gist.github.com/sinisterchipmunk/1335041
require 'rubygems/package'
require 'fileutils'
require 'zlib'

def create_tar(path, opts={})
  tarfile = StringIO.new("")
  Gem::Package::TarWriter.new(tarfile) do |tar|
    Dir[File.join(path, "**/*")].each do |file|
      mode = File.stat(file).mode

      if opts[:relative_file]
        relative_file = file.sub(/^#{Regexp::escape path}\/?/, '')
      else
       relative_file = file.sub %r|^/|, ''
      end

      if File.directory?(file)
        tar.mkdir relative_file, mode
      else
        tar.add_file relative_file, mode do |tf|
          File.open(file, "rb") { |f| tf.write f.read }
        end
      end
    end
  end

  tarfile.rewind
  tarfile
end

def gzip(tarfile)
  gz = StringIO.new("")
  z = Zlib::GzipWriter.new(gz)
  z.write tarfile.string
  z.close # this is necessary!

  # z was closed to write the gzip footer, so
  # now we need a new StringIO
  StringIO.new gz.string
end

def ungzip(tarfile)
  tarfile.rewind
  z = Zlib::GzipReader.new(tarfile)
  unzipped = StringIO.new(z.read)
  z.close
  unzipped
end

def untar(io, destination)
  io.rewind
  Gem::Package::TarReader.new io do |tar|
    tar.each do |tarfile|
      destination_file = File.join destination, tarfile.full_name

      if tarfile.directory?
        FileUtils.mkdir_p destination_file
      else
        destination_directory = File.dirname(destination_file)
        FileUtils.mkdir_p destination_directory unless File.directory?(destination_directory)
        File.open destination_file, "wb" do |f|
          f.print tarfile.read
        end
      end
    end
  end
end