python subprocess模块 监控子进程的2种方式 忙等待和立即返回同时设置子进程超时时间，pythonsubprocess,一:循环 忙等 子进程结

python subprocess模块 监控子进程的2种方式 忙等待和立即返回同时设置子进程超时时间，pythonsubprocess,一:循环 忙等 子进程结

一:循环 忙等 子进程结束

import subprocess  import os  import time  tt = '555'  cmd = "python /home/100003/python/mypython/sub2.py "+" 333"+" 444 "+tt  print time.time()  sub2 = subprocess.Popen(cmd, shell=True)  while 1:      ret1 = subprocess.Popen.poll(sub2)      if ret1 == 0:          print sub2.pid,'end'          break      elif ret1 is None:          print  'running'          time.sleep(1)      else:          print sub2.pid,'term'          break  print time.time()  

                                二:子进程结束 立即返回 使用select模块 同时可设置子进程的超时时间

import subprocess  import select  import time  import signal  import os  tt = '555'  cmd = "python /home/100003/python/mypython/sub2.py "+" 333"+" 444 "+tt  timeout = 3  pro = subprocess.Popen(cmd, stdout=subprocess.PIPE,shell = True)  print time.time()  while 1:      while_begin = time.time()      print 'timeout',timeout      fs = select.select([pro.stdout], [], [], timeout)      if pro.stdout in fs[0]:          tmp = pro.stdout.read()          print 'read', tmp          if not tmp:              print 'end'              print time.time()              break      else:          print 'outoftime'          print os.kill(pro.pid, signal.SIGKILL),          break      timeout = timeout - (time.time() - while_begin)