#/usr/bin/env python3 # Copyright 2011 Florent Le Coz <louiz@louiz.org> # # This file is part of Poezio. # # Poezio is free software: you can redistribute it and/or modify # it under the terms of the zlib license. See the COPYING file. """ This file is a standalone program that reads commands on stdin and executes them (each line should be a command). Usage: cat some_fifo | ./daemon.py Poezio writes commands in the fifo, and this daemon executes them on the local machine. Note that you should not start this daemon if you do not trust the remote machine that is running poezio, since this could make it run any (dangerous) command on your local machine. """ import sys import threading import subprocess import shlex import logging try: from subprocess import DEVNULL # Only in python >= 3.3 except ImportError: import os DEVNULL = open(os.devnull, 'wb') log = logging.getLogger(__name__) class Executor(threading.Thread): """ Just a class to execute commands in a thread. This way, the execution can totally fail, we don’t care, and we can start commands without having to wait for them to return. WARNING: Be careful to properly escape what is untrusted by using pipes.quote (or shlex.quote with python 3.3) for example. """ def __init__(self, command, remote=False): threading.Thread.__init__(self) self.command = command self.remote = remote # check for > or >> special case self.filename = None self.redirection_mode = 'w' if len(command) >= 3: if command[-2] in ('>', '>>'): self.filename = command.pop(-1) if command[-1] == '>>': self.redirection_mode = 'a' command.pop(-1) def run(self): print("executing %s" % (self.command)) log.debug('executing %s', self.command) stdout = DEVNULL if self.filename: try: stdout = open(self.filename, self.redirection_mode) except (OSError, IOError): log.error('Could not open redirection file: %s', self.filename, exc_info=True) return try: subprocess.call(self.command) except: if self.remote: import traceback print(traceback.format_exc()) else: log.error('Could not execute %s:', self.command, exc_info=True) def main(): while True: line = sys.stdin.readline() if line == '': break command = shlex.split(line) e = Executor(command, remote=True) e.start() if __name__ == '__main__': main()