How to terminate a python subprocess launched with shell=True (轉貼)

How to terminate a python subprocess launched with shell=True

391

I'm launching a subprocess with the following command:

p = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)

However, when I try to kill using:

p.terminate()

or

p.kill()

The command keeps running in the background, so I was wondering how can I actually terminate the process.

Note that when I run the command with:

p = subprocess.Popen(cmd.split(), stdout=subprocess.PIPE)

It does terminate successfully when issuing the p.terminate().

pythonlinuxsubprocesskill-process

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edited Oct 21, 2012 at 12:48

Piotr Dobrogost

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asked Jan 25, 2011 at 3:58

user175259

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• What does your cmd look like? It might contain a command which triggers several processes to be started. So it’s not clear which process you talk about. 

  – Robert Siemer

   Nov 27, 2014 at 15:47
• 2
  related: Python: how to kill child process(es) when parent dies? 

  – jfs

   Jan 23, 2015 at 15:08
• 1
  does not having shell=True make a big difference? 

  – Charlie Parker

   Mar 7, 2019 at 19:46

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501

Use a process group so as to enable sending a signal to all the process in the groups. For that, you should attach a session id to the parent process of the spawned/child processes, which is a shell in your case. This will make it the group leader of the processes. So now, when a signal is sent to the process group leader, it's transmitted to all of the child processes of this group.

Here's the code:

import os
import signal
import subprocess

# The os.setsid() is passed in the argument preexec_fn so
# it's run after the fork() and before  exec() to run the shell.
pro = subprocess.Popen(cmd, stdout=subprocess.PIPE, 
                       shell=True, preexec_fn=os.setsid) 

os.killpg(os.getpgid(pro.pid), signal.SIGTERM)  # Send the signal to all the process groups

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What is file path ../..

 

php include with ".." before file path

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Asked 7 years, 5 months ago

Modified 7 years, 5 months ago

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3

I recently was watching a php video tutorial and the author was showing how to do include a file. He was using XAMPP for the demonstrations and had many files.

When he was showing how to include a file, he mentioned something about putting two dots (..) in front of the file path (/xampp/content/example.html) because of something having to do with where the files were located, assuming that I already had knowledge of this principle. But i don't.

Can anyone explain what is up with having one dot or two dots in front of file paths?

What is the difference between include("/xampp/content/example.html");, include("./xampp/content/example.html");, and include("../xampp/content/example.html");

phpinclude-path

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asked Feb 10, 2015 at 3:43

krummens

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In Linux / Unix environment,

/xampp/content/example.html means absolute path

./xampp/content/example.html means relative path of current directory

../xampp/content/example.html means relative path of parent directory

For the folder structure: /var/www/xampp/content/example3.html:

If your current folder is /var/www/...

• ../ (goes up 1 level) will be /var/
• ./ (in current level) will be /var/www/
• / will be / (in Linux, / means the root of the server, the outermost structure of the filesystem)
• ../../ (goes up 2 level) will be /

There are 2 types of paths: Relative Path & Absolute Path.

For Relative path, it's relative to your current directory. For absolute path, it's not related to your current directory.