tar_test.rb

require 'rubygems'
require 'archive/tar/minitar'

src = {
  "foo.txt" => "This is file foo",
  "bar.txt" => "This is file bar",
}

File.open("test.tar","w") do |tarfile|
  Archive::Tar::Minitar::Writer.open(tarfile) do |tar|
    src.each do |name, data|
      tar.add_file_simple(name, :size=>data.size, :mode=>0644) { |f|
        f.write(data) }
    end
  end
end