Python subprocess logging to logger from stdout/stderr

logging_subprocess.py

#!/usr/local/bin/python3

import logging, select, subprocess

LOG_FILE = "test.log"
logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO,filename=LOG_FILE,format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')

def logging_call(popenargs, **kwargs):
    process = subprocess.Popen(popenargs, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

    def check_io():
           while True:
                output = process.stdout.readline().decode()
                if output:
                    logger.log(logging.INFO, output)
                else:
                    break

    # keep checking stdout/stderr until the child exits
    while process.poll() is None:
        check_io()

def main():
    logging_call(["ls", "-l"])

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        logging.warning("Stopping...")

Hi 👋

I've done a rewrite from scratch:

• Using py 3.7+ text kwarg so it works on Windows special chars as well
• Using two threads in order to handle stdout and stderr separately i.e. logging.INFO and logging.ERROR

https://gist.github.com/ddelange/6517e3267fb74eeee804e3b1490b1c1d