Python get env from finished subprocess-CodePudding

python3.9

So I have a subprocess like so


m_env = os.environ.copy()

process = subprocess.Popen(
    ['export', 'TEST=test'],
    env=m_env,
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
    shell=True
)
result = process.wait()

new_env = process.getenv() #how to get this so the new_env has the 'TEST=test' in it.

Now the subprocess itself is modifying the env, and i wanna know how can i get this modified env from the process, the example is using export, however i run a script which may change or add other env variables, so i'd like to get the whole env.

CodePudding user response：

You can print all the environment variables in the subprocess shell, but you have to parse the data afterwards.

import os
import subprocess

def main():
    m_env = os.environ.copy()
    process = subprocess.Popen(
        ['export TEST=test && export'],
        env=m_env,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        shell=True
    )
    process.wait()
    print(process.stdout.read()) # all environment variables


if __name__ == '__main__':
    main()

Edit: Changed environment printing function from printenv (which can be ambiguous when parsing) to export. Thanks to Charles Duffy

CodePudding user response：

The solution posted by @Pavel Hamerník was the starting point. With the guidance of comment discussions from @Charles Duffy, the following solution is what works best for my implementation.

import os
import subprocess

def main():
    m_env = os.environ.copy()
    process = subprocess.Popen(
        ['/bin/bash', '-c', '. /path/script.sh && export > /tmp/env.txt'],
        env=m_env,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        shell=True
    )
    process.wait()
    print(process.stdout.read()) # read the stdout from script


if __name__ == '__main__':
    main()

Note: the export output is being directed to a file in /tmp/.