text: #!/usr/bin/env python
  import subprocess
  import os, sys, time, signal, pty
  
  master, slave = pty.openpty()
  
  p = subprocess.Popen(["setsid", "--ctty", "sleep", "10000"],
                       stdin=slave,
                       stdout=slave,
                       stderr=slave,
                       close_fds=True)
  st = os.stat("/proc/self/fd/%d" % slave)
  ttyid = "tty[%x:%x]" % (st.st_rdev, st.st_dev)
  os.close(slave)
  time.sleep(1)
  
  ret = subprocess.Popen([
      "../../../criu/criu", "dump", "-t",
      str(p.pid), "-v4", "--external", ttyid
  ]).wait()
  if ret:
      sys.exit(ret)
  p.wait()
  
  new_master, slave = pty.openpty()  # get another pty pair
  os.close(master)
  
  ttyid = "fd[%d]:tty[%x:%x]" % (slave, st.st_rdev, st.st_dev)
  
  ret = subprocess.Popen([
      "../../../criu/criu", "restore", "-v4", "--inherit-fd", ttyid,
      "--restore-sibling", "--restore-detach"
  ]).wait()
  if ret:
      sys.exit(ret)
  os.close(slave)
  os.waitpid(-1, os.WNOHANG)  # is the process alive
  
  os.close(new_master)
  _, status = os.wait()
  if not os.WIFSIGNALED(status) or os.WTERMSIG(status) != signal.SIGHUP:
      print(status)
      sys.exit(1)
  
  print("PASS")
  