[run bash command](use subprocess to pip stderr and stdout) #subprocess #Popen #stdout #stderr #bash

run_command.py

def run_command(cmd_to_run):
    """
    Wrapper around subprocess that pipes the stderr and stdout from `cmd_to_run`
    to temporary files. Using the temporary files gets around subprocess.PIPE's
    issues with handling large buffers.

    Note: this command will block the python process until `cmd_to_run` has completed.

    Returns a tuple, containing the stderr and stdout as strings.
    """
    with tempfile.TemporaryFile() as stdout_file, tempfile.TemporaryFile() as stderr_file:

        # Run the command
        popen = subprocess.Popen(cmd_to_run, stdout=stdout_file, stderr=stderr_file)
        popen.wait()

        stderr_file.seek(0)
        stdout_file.seek(0)

        stderr = stderr_file.read()
        stdout = stdout_file.read()

        return stderr, stdout