daemon.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from threading import Thread
import subprocess
import logging
import os

SCREEN_LOCK = ["sudo", "-u", "devunt", "/usr/bin/gnome-screensaver-command", "-a"]
SCREEN_UNLOCK = ["sudo", "-u", "devunt", "/usr/bin/gnome-screensaver-command", "-d"]
HCITOOL = "/usr/local/bin/hcitool"
HCIDUMP = "/usr/local/bin/hcidump"
MAC_ADDR = "C9:C5:D6:14:51:C7"

class LEScanThread(Thread):
    def __init__(self):
        self.cmd = [HCITOOL, "lescan"]
        Thread.__init__(self)

    def run(self):
        while 1:
            with open(os.devnull, "w") as f:
                self.p = subprocess.Popen(self.cmd,
                        stdout=f,
                        stderr=f)
                self.p.wait()

    def abort(self):
        self.p.termiate()

class BTMonThread(Thread):
    def __init__(self):
        self.cmd = [HCIDUMP]
        Thread.__init__(self)

    def run(self):
        flag = False
        locked = False
        cnt = 0
        p = subprocess.Popen(self.cmd,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT)
        for line in iter(p.stdout.readline, b''):
            line = p.stdout.readline().strip()
            if line == 'bdaddr %s (Random)' % MAC_ADDR:
                flag = True
            elif flag and line.startswith('RSSI: '):
                flag = False
                rssi = int(line[6:])
                logging.debug('RSSI: %d' % rssi)
                if locked:
                    if rssi >= -80: cnt += 1
                    elif cnt > 0: cnt = 0
                    if cnt >= 5:
                        cnt = 0
                        locked = False
                        subprocess.Popen(SCREEN_UNLOCK)
                        logging.info('unlock()')
                else:
                    if rssi < -80: cnt += 1
                    elif cnt > 0: cnt = 0
                    if cnt >= 5:
                        cnt = 0
                        locked = True
                        subprocess.Popen(SCREEN_LOCK)
                        logging.info('lock()')

if __name__ == "__main__":
    logging.basicConfig(level=logging.DEBUG, format='[%(asctime)s] {%(levelname)s} %(message)s')
    lescan_th = LEScanThread()
    lescan_th.daemon = True
    lescan_th.start()
    btmon_th = BTMonThread()
    try:
        btmon_th.start()
    except KeyboardInterrupt:
        logging.critical('abort!')
        lescan_th.abort()