openxml/openxml-pptx

#!/usr/bin/env ruby

require "zip"
require "pathname"
require "shellwords"

# c.f. https://github.com/rubyzip/rubyzip/blob/05916bf89181e1955118fd3ea059f18acac28cc8/samples/example_recursive.rb
class ZipFileGenerator

  def initialize(input_dir, output_file)
    @input_dir = Pathname(input_dir)
    @output_file = Pathname(output_file)
  end

  def write
    @output_file.delete if @output_file.exist?
    Zip::File.open(@output_file, Zip::File::CREATE) do |io|
      write_entries entries_in(@input_dir), "", io
    end
  end

  private def write_entries(entries, path, io)
    entries.each do |entry|
      zip_file_path = path == "" ? entry : File.join(path, entry)
      disk_file_path = File.join(@input_dir, zip_file_path)
      if File.directory?(disk_file_path)
        io.mkdir zip_file_path
        write_entries entries_in(disk_file_path), zip_file_path, io
      else
        io.get_output_stream(zip_file_path) do |stream|
          stream.puts File.open(disk_file_path, "rb").read
        end
      end
    end
  end

  private def entries_in(path)
    entries = Dir.entries(path)
    entries.delete(".")
    entries.delete("..")
    entries.delete(".DS_Store")
    entries
  end

end



path = Pathname.new(ARGV.shift)

if path.directory?
  zf = ZipFileGenerator.new(path, "#{path.basename}.pptx")
  zf.write
else
  system "unzip #{Shellwords.escape path} -d #{path.basename(".pptx")}"
end