subprocess.Popen shell=True to shell=False

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Track title: CC G Dvoks String Quartet No 12 Ame 2

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Chapters
00:00 Question
00:36 Accepted answer (Score 8)
01:02 Answer 2 (Score 0)
01:25 Thank you

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Full question
https://stackoverflow.com/questions/4147...

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https://meta.stackexchange.com/help/lice...

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Tags
#python #shell #subprocess

#avk47

ACCEPTED ANSWER

Score 8

You can't directly use piping in the command the way you do with shell=True, but it's easy to adapt:

with open(file_name, 'ab') as outf:
    proc = subprocess.Popen(['candump', '-tA', 'can0', 'can1'], stdout=outf)

That opens the file at the Python level for binary append, and passes it as the stdout for the subprocess.

ANSWER 2

Score 0

Only shell mode supports inline piping operators so you'll need to do the redirection manually. Also, you'll need to split your command line into individual arguments which you can either do manually or have the shlex module do for you:

subprocess.Popen(shlex.split('candump -tA can0 can1'), stdout=open(file_name, 'ab'))