gistfile1.rb

    start_time = timestamp

    open = true

    status = Open4.popen4(command) do |pid, _, out, err|
      while(open)
        elapsed = (timestamp - start_time) 

        if elapsed > CommandTimeout
          out.close rescue puts "out close err"
          err.close rescue puts "err close err"

          # quite hackish, but works.
          Process.kill(15, pid) rescue puts $!.inspect

          raise ConversionError.new(
            'Timeout while converting after %01.3f seconds (Timeout %01.3f).' % [
              elapsed,
              CommandTimeout
            ])
        end

        if ready = IO.select([out], [err], nil, (1.0 / 24))
          if ready.flatten.include?(out)
            begin
              while(data = out.readpartial(4096))
                out += data
              end
            rescue EOFError => e
              open = false
            end
          end

          if ready.flatten.include?(err)
            begin
              while(data = err.readpartial(4096))
                err_output += data
              end
            rescue EOFError => e
              open = false
            end
          end
        else
          # No data available right now or we've read all of it.
        end
      end
    end