Run system commands in Python

syscmd.py

"""
NOTE: This requires Python 3.9+ simply due to the use of "tuple" as a type hint.
If you remove type hints this works back to at least 3.4, and likely older.
"""


import subprocess
import sys

def syscmd(cmd: str) -> tuple[int, bytes]:
  """
  Runs a command on the system, waits for the process to exit, and then returns
  a tuple containing the return code and the text output of the command. This is
  meant as a "no fuss" solution to subprocesses in Python. It works on Windows
  and Linux. It returns all output, error messages, and return codes without
  throwing exceptions if the command fails or is not found.

  Usage (Windows):

  >>> syscmd("cd C:/")
  (0, b'')

  >>> syscmd("cd /nonexistent")
  (1, b'The system cannot find the path specified.')

  >>> syscmd("nonexistent") #doctest: +ELLIPSIS
  (1, b"'nonexistent' is not recognized as an internal or ...")
  """
  p = subprocess.Popen(
    cmd, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
    stderr=subprocess.STDOUT, close_fds=(not sys.platform == "win32"))
  p.wait()
  output = p.stdout.read()
  if len(output) > 1:
    output = output.strip()
  return p.returncode, output