Run subprocess and print output to logging

Question

I am looking for the way to call shell scripts from python and write their stdout and stderr to file using logging. Here is my code:

Answer 1

You could try to pass the pipe directly without buffering the whole subprocess output in memory:

from subprocess import Popen, PIPE, STDOUT

process = Popen(command_line_args, stdout=PIPE, stderr=STDOUT)
with process.stdout:
    log_subprocess_output(process.stdout)
exitcode = process.wait() # 0 means success

where log_subprocess_output() could look like:

def log_subprocess_output(pipe):
    for line in iter(pipe.readline, b''): # b'\n'-separated lines
        logging.info('got line from subprocess: %r', line)