Runs specified commands on ctrl-w press

ctrlwmonitor.py

import evdev
from select import select
from sys import argv, exit
from os import system

TRIGGER_KEY = evdev.ecodes.KEY_W
TRIGGER_MODIFIER_DISJUNCTIVE = set((evdev.ecodes.KEY_LEFTCTRL, evdev.ecodes.KEY_RIGHTCTRL))

keysDown = set()

monitored = []
selectList = {}

def getKeyboardDevices():
    devices = []
    for d in [evdev.InputDevice(path) for path in evdev.list_devices()]:
        c = d.capabilities(verbose=True)
        try:
            if ('KEY_W',17) in c[('EV_KEY', 1)]:
                devices.append(d)
        except:
            pass
    return devices

def updateMonitoring():
    global monitored,selectList
    current = getKeyboardDevices()
    changed = False
    for d in current:
        if d not in monitored:
            changed = True
            break
    if not changed:
        for d in monitored:
            if d not in current:
                changed = True
    if changed:
        monitored = current
        selectList = {d.fd:d for d in current}
    return changed

def disjunctiveIn(disjunction, list):
    for d in disjunction:
        if d in list:
            return True
    return False

while True:
    updateMonitoring()
    try:
        r, w, x = select(selectList, [], [], 0.25)
        for fd in r:
            for event in selectList[fd].read():
                if event.type == evdev.ecodes.EV_KEY:
                    if not event.value:
                        if event.code in keysDown:
                            keysDown.remove(event.code)
                    else:
                        keysDown.add(event.code)
                    if event.value and event.code == TRIGGER_KEY and disjunctiveIn(TRIGGER_MODIFIER_DISJUNCTIVE, keysDown):
                        for cmd in argv[1:]:
                            if cmd == '-exit':
                                exit(0)
                            else:
                                system(cmd)
    except KeyboardInterrupt:
        exit(0)
    except:
        pass