Question

我从基准脚本中复制了部分Python脚本，并尝试在进行修改后执行它。问题是，它一旦启动就会挂起。

Python脚本是：

# !/usr/bin/python

# =============================
# initialize & configure
# =============================
#import shlex
#import fnmatch
import os
import subprocess
import resource
import os, sys, cPickle, time, threading, signal

from errno import EEXIST
from os.path import join
from subprocess import Popen
#from domain import Record
from threading import Timer



def measure(commandline):

#   r,w = os.pipe()
   forkedPid = os.fork()

   if forkedPid: # read pickled measurements from the pipe

      print "Parent proc start and the child pid: ", forkedPid
 #     os.close(w); rPipe = os.fdopen(r); r = cPickle.Unpickler(rPipe)
 #     measurements = r.load()
 #     rPipe.close()
      os.waitpid(forkedPid,0)
      print "Parent proc end"
      return "------------"

   else: 
      # Sample thread will be destroyed when the forked process _exits
      class Sample(threading.Thread):

         def __init__(self,program):
            threading.Thread.__init__(self)
            self.setDaemon(1)
            self.timedout = False 
            self.p = program
            self.maxMem = 0
            self.childpids = None   
            self.start() 

         def run(self):
            try:              
               remaining = maxtime
               delay=0.01
               print "Start run deman thread: ", remaining, "delay", delay
               while remaining > 0:                                   
                  res = resource.getrusage(resource.RUSAGE_CHILDREN)

                  time.sleep(delay)                    
                  remaining -= delay
                  print "\n res: ",res, " and remaining is: ", remaining

               else:
                  self.timedout = True
                  os.kill(self.p, signal.SIGKILL) 
            except OSError, (e,err):
                print "Error ", err


      try:

         print "Child proc ", commandline

         # only write pickles to the pipe
       #  os.close(r); wPipe = os.fdopen(w, 'w'); w = cPickle.Pickler(wPipe)

         start = time.time()

         # print "commandLine: ", commandline, " remaining: ",remaining
         # spawn the program in a separate process
         p = Popen(commandline,stdout=outFile,stderr=errFile,stdin=inFile, shell=True)


         # start a thread to sample the program's resident memory use
         t = Sample( program = p.pid )
         print "Child ......"
         # wait for program exit status and resource usage
         rusage = os.wait3(0)
         print 'rusage: ', rusage
         elapsed = time.time() - start

       #  m.userSysTime = rusage[2][0] + rusage[2][1]
       #  m.maxMem = t.rusage
       #  m.cpuLoad = "%"
       #  m.elapsed = elapsed
         print "Child proc end"

      except KeyboardInterrupt:
          print "keyBordInterrupt..."
          os.kill(p.pid, signal.SIGKILL)

      except ZeroDivisionError, (e,err): 
          print " error ZeroDiv: "

      except (OSError,ValueError), (e,err):
          print " error ", e
      finally:
          print "Here is finally section. "
         #w.dump(m)
         # wPipe.close()

         # Sample thread will be destroyed when the forked process _exits
          os._exit(0)

if __name__ == '__main__':
    print "Start now...."
#measure("jruby  \/tmp/test.rb")

当我使用ps -ef | grep MyAccount时，我发现解释器会挂在第一个`import指令上：

  MyAccount    16934 16933  0 12:08 pts/19   00:00:00 import os

/tmp/test.rb是一个单行的Ruby脚本（puts "hello"），它不会引起任何问题，因为它已经被注释掉了。

我跑了ps -ef | grep MyAccount三分钟，这一个总是在那里。此外，控制台中没有任何输出，我希望看到Start now....。

Answer 1

这是因为您的代码不是解释为Python脚本，而是解释为Bash脚本。

第一行应该是

#!/usr/bin/python

而不是

# !/usr/bin/python

您可以跳过此行，只需使用

运行程序即可

python <your_script.py>

而不是

./<your_script.py>

我还认为您错误地阅读了ps个结果。

ps -ef的最后一列是命令的名称，绝对不是脚本的一行，第一列是MyAccount，是用户的名称。

因此，此ps输出表示进程import os已挂起。在某些Linux发行版中有一个名为import的应用程序，请参阅man import。如果您尝试从shell执行它：

$import os

它只是永远等待输入（直到中断），这就是发生在你身上的事情。

Python挂起首次导入

1 个答案: