syaberu.rb

require 'open_jtalk'
require 'tmpdir'
require 'readline'

class Talk
  def start
    tmpdir = Dir.mktmpdir('syaberu.rb')
    while string = Readline.readline('> ', true)
      say(string, tmpdir)
    end
  ensure
    FileUtils.remove_entry_secure(tmpdir)
  end

  private

  def say(string, working_dir)
    make_voicefile(string, working_dir)
    system('play', '-q', "#{working_dir}/output.wav")
  end

  def make_voicefile(string, output_dir)
    OpenJtalk.load(OpenJtalk::Config::Mei::LOW) do |openjtalk|
      header, data = openjtalk.synthesis(openjtalk.normalize_text(string))
      OpenJtalk::WaveFileWriter.save("#{output_dir}/output.wav", header, data)
    end
  end
end

Talk.new.start