gistfile1.txt

def popen4(*cmd)
  # Use IO.popen4 for JRuby < 9.0.0.0
  return IO.popen4(*cmd) unless jruby9k?

  opts = {}
  in_r, in_w = IO.pipe
  opts[:in] = in_r
  in_w.sync = true

  out_r, out_w = IO.pipe
  opts[:out] = out_w

  err_r, err_w = IO.pipe
  opts[:err] = err_w

  child_io = [in_r, out_w, err_w]
  parent_io = [in_w, out_r, err_r]

  pid = spawn(*cmd, opts)
  wait_thr = Process.detach(pid)
  child_io.each { |io| io.close }
  result = [pid, *parent_io]
  if defined? yield
    begin
      return yield(*result)
    ensure
      parent_io.each { |io| io.close unless io.closed? }
      wait_thr.join
    end
  end
  result
end