如何在Python中调用具有指定时间限制的系统命令?

时间:2014-12-21 11:28:10

标签: python multithreading

我正在创建一个调用一些系统命令的Python应用程序。但是,如果它们花费太多时间(比如10s),我希望它终止这些命令。我尝试使用一些子过程自己做这件事 - 没有太大的成功。在stackoverflow上搜索后,我发现了以下问题: Using module 'subprocess' with timeout

它有一个答案,几乎对我有用 - 问题是,当进程终止&#34;时,它实际上不是< / em> - 事实上,即使我的脚本完成后,该过程仍在后台运行。当然这不是一个理想的效果,但我无法找到解决方法。是否有解决此问题的优先解决方案?

来自上述答案的代码(不良代码)供参考:

import subprocess, threading

class Command(object):
    def __init__(self, cmd):
        self.cmd = cmd
        self.process = None

    def run(self, timeout):
        def target():
            print 'Thread started'
            self.process = subprocess.Popen(self.cmd, shell=True)
            self.process.communicate()
            print 'Thread finished'

        thread = threading.Thread(target=target)
        thread.start()

        thread.join(timeout)
        if thread.is_alive():
            print 'Terminating process'
            self.process.terminate()
            thread.join()
        print self.process.returncode

command = Command("echo 'Process started'; sleep 2; echo 'Process finished'")
command.run(timeout=3)
command.run(timeout=1)

1 个答案:

答案 0 :(得分:1)

你可以在这里找到答案:

How to terminate a python subprocess launched with shell=True

只需将preexec_fn=os.setsid添加到Popen命令

即可

终止使用:

os.killpg(self.process.pid, signal.SIGTERM)

而不是:

self.process.terminate()

别忘了import os,signal

所以你会得到:

import subprocess, threading
import os,signal
class Command(object):
    def __init__(self, cmd):
        self.cmd = cmd
        self.process = None

    def run(self, timeout):
        def target():
            print 'Thread started'
            self.process = subprocess.Popen(self.cmd, shell=True, preexec_fn=os.setsid)
            self.process.communicate()
            print 'Thread finished'

        thread = threading.Thread(target=target)
        thread.start()

        thread.join(timeout)
        if thread.is_alive():
            print 'Terminating process'
            os.killpg(self.process.pid, signal.SIGTERM)
            thread.join()
        print self.process.returncode

command = Command("echo 'Process started'; sleep 2; echo 'Process finished'")
command.run(timeout=3)
command.run(timeout=1)