diff --git a/c4ctrl.py b/c4ctrl.py
index 2248c64..4e3d379 100755
--- a/c4ctrl.py
+++ b/c4ctrl.py
@@ -1,23 +1,26 @@
 #!/usr/bin/env python3
-#
-# c4ctrl: Command line client for AutoC4
-#
-# Author: Shy
 
 """
-This is a command line client for Autoc4, the home automation system of the C4.
+A command line client for Autoc4, the home automation system of the C4.
 
-Some parts of it **may** be useful as python module for simple tasks.
+May be useful as python module for simple tasks.
+
+Dependencies:
+    Paho Python Client
+    (available from https://github.com/eclipse/paho.mqtt.python)
 """
 
+__date__ = "07 April 2017" 
+__author__ = "Shy"
+
 import sys
 
 
 class C4Interface():
-    """ Interaction with the C4 home automation system. """
+    """ Interaction with AutoC4, the C4 home automation system. """
 
-    port = 1883
     broker = "autoc4.labor.koeln.ccc.de"
+    port = 1883
     qos = 2
     retain = True
     debug = False
@@ -26,20 +29,21 @@ class C4Interface():
         # Set a default topic
         if topic: self.topic = topic
 
-    def push(self, cmd, topic=None, retain=None):
+    def push(self, message, topic=None, retain=None):
         """ Send a message to the MQTT broker.
             
-            cmd may a byte encoded payload or a list of byte encoded
+            message may a byte encoded payload or a list of byte encoded
             payloads. """
+
         from paho.mqtt import publish
 
         # Overwrite defaults
         if topic: self.topic = topic
         if retain != None: self.retain = retain
 
-        if type(cmd) == list:
+        if type(message) == list:
             # Add <qos> and <retain> to every message
-            for item in cmd.copy():
+            for item in message.copy():
                 if type(item) == dict:
                     item["qos"] = self.qos
                     item["retain"] = self.retain
@@ -50,22 +54,22 @@ class C4Interface():
                         self.qos, # qos
                         self.retain # retain
                         )
-                    cmd.remove(item)
-                    cmd.append(new_item)
+                    message.remove(item)
+                    message.append(new_item)
                         
-            if self.debug: return print("[DEBUG] inhibited messages:", cmd)
+            if self.debug: return print("[DEBUG] inhibited messages:", message)
 
-            publish.multiple(cmd,
+            publish.multiple(message,
                     hostname=self.broker,
                     port=self.port)
 
-        else:
+        else: # Message is not a list
             if self.debug:
                 return print("[DEBUG] inhibited message to '{}': '{}'".format(
-                        self.topic, cmd))
+                        self.topic, message))
 
             publish.single(self.topic,
-                    payload=cmd,
+                    payload=message,
                     qos=self.qos,
                     retain=self.retain,
                     hostname=self.broker,
@@ -75,7 +79,9 @@ class C4Interface():
         """ Return the state of a topic.
             
             topic may be a list of topics or a single topic given as string. """
+
         from paho.mqtt import subscribe
+
         topic = topic or self.topic
         # <topic> must be a list
         if type(topic) == str:
@@ -93,6 +99,7 @@ class C4Interface():
 
     def status(self):
         """ Returns current status (string "open" or "closed") of the club. """
+
         st = self.pull("club/status")
 
         # Produce fake result to prevent errors if in debug mode
@@ -108,15 +115,17 @@ class C4Interface():
 
     def open_gate(self):
         """Open the gate."""
-        self.push(cmd=b'\x01', topic="club/gate", retain=False)
+
+        self.push(None, topic="club/gate", retain=False)
 
     def shutdown(self, force=False):
         """Invoke the shutdown routine.""" 
+
         if force:
             payload = b'\x44'
         else:
             payload = b'\x00'
-        self.push(cmd=payload, topic="club/shutdown", retain=False)
+        self.push(payload, topic="club/shutdown", retain=False)
 
 
 class Dmx:
@@ -179,27 +188,19 @@ class C4Room:
 
     def __init__(self):
         self.c4 = C4Interface()
+        self.switch_state = "" # State of switches in the like of str("0010")
 
     def _interactive_light_switch(self):
-        # Interactively ask for input
+        """ Interactively ask for input. Returns str(userinput). """
+
         if sys.stdin.isatty():
             print("[{}]".format(self.name))
             print("Please enter 0 or 1 for every light:")
             for level in range(len(self.switches)):
                 print((level * '|') + ",- " + self.switches[level][0])
 
-            # Current state of switches
-            state = ""
-            req = []
-            for t in self.switches:
-                req.append(t[1])
-            responce = self.c4.pull(req)
-            for sw in self.switches:
-                for r in responce:
-                    if r.topic == sw[1]:
-                        state = state + str(int.from_bytes(r.payload,
-                                byteorder="little"))
-            print(state) # Present current state
+            self.switch_state = self._get_state()
+            print(self.switch_state) # Present current state
 
         try:
             userinput = sys.stdin.readline().rstrip('\n')
@@ -209,42 +210,84 @@ class C4Room:
 
         return userinput
 
+    def _get_state(self):
+        """ Returns current state of switches as a str() of 1s and 0s. """
+
+        state = ""
+        req = []
+        for topic in self.switches:
+            req.append(topic[1])
+        responce = self.c4.pull(req)
+        for sw in self.switches:
+            for r in responce:
+                if r.topic == sw[1]:
+                    state += str(int.from_bytes(r.payload, byteorder="little"))
+
+        return state
+
     def light_switch(self, userinput=""):
         """ Switch lamps in a room on or off. """
 
         if not userinput:
+            # Derive user input from stdin
             userinput = self._interactive_light_switch()
             if userinput == "": return
 
+        mode = 'n' # n = normal, a = AND, o = OR
         if not userinput.isdecimal():
-            print("You're not paying attention!", file=sys.stderr)
-            return
+            if userinput[0] == '&' and userinput[1:].isdecimal():
+                # AND operator
+                userinput = userinput[1:]
+                mode = 'a'
+            elif userinput[0] == '|' and userinput[1:].isdecimal():
+                # OR operator
+                userinput = userinput[1:]
+                mode = 'o'
+            else:
+                print("You're not paying attention!", file=sys.stderr)
+                return
 
         if len(userinput) != len(self.switches):
+            # First try to convert from integer if userinput's length doesn't
+            # match
             if len(bin(int(userinput))) <= len(self.switches)+2:
-                # +2 because bin() returns something like 'b0...'
-                # Try to interpret as integer
-                binary = bin(int(userinput))[2:]
-                userinput = str(len(self.switches)*'0')[:-len(binary)] + binary
+                # ^ +2 because bin() returns strings like 'b0...'
+                binary = bin(int(userinput))[2:] # Strip leading 'b0'
+                # Pad with leading zeroes
+                userinput = binary.rjust(len(self.switches), '0')
             else:
                 print("Error: wrong number of digits (expected {}, got {})!".format(
                         len(self.switches), len(userinput)))
                 return False
 
-        cmd=[]
-        for si in range(len(self.switches)):
-            if userinput[si] not in "01":
-                print("Error: invalid digit: " + userinput[si])
+        # Now that everything special is expanded it's time to check if
+        # userinput really consists of 1s and 0s only
+        for digit in userinput:
+            if digit not in "01":
+                print("Error: invalid digit: " + digit, file=sys.stderr)
                 return False
-            cmd.append({
-                "topic" : self.switches[si][1],
-                "payload" : bytearray([int(userinput[si])])
+
+        if mode == 'a': # AND operator
+            if not self.switch_state: self.switch_state = self._get_state()
+            userinput = "".join(map(lambda x, y: str(int(x) & int(y)),
+                                    userinput, self.switch_state))
+        elif mode == 'o': # OR operator
+            if not self.switch_state: self.switch_state = self._get_state()
+            userinput = "".join(map(lambda x, y: str(int(x) | int(y)),
+                                    userinput, self.switch_state))
+
+        command=[]
+        for i in range(len(self.switches)):
+            command.append({
+                "topic" : self.switches[i][1],
+                "payload" : bytearray([int(userinput[i])])
             })
 
-        return self.c4.push(cmd)
+        return self.c4.push(command)
 
     def set_colorscheme(self, colorscheme, magic):
         """ Apply colorscheme to the LED Cans in this room. """
+
         cmd = []
         for light in self.lights:
             if colorscheme.color_for(light.topic):
@@ -383,6 +426,7 @@ class Kitchenlight:
 
     def _switch(self, data, poweron=False, poweroff=False):
         """ Send commands via a C4Interface to the MQTT broker. """
+
         if self.autopower or poweron or poweroff:
             c4 = C4Interface(self.topic)
             cmd = []
@@ -404,6 +448,7 @@ class Kitchenlight:
 
     def set_mode(self, mode, opts=[]):
         """Switch to given mode."""
+
         mode = mode.lower()
         if mode == "off":
             return self.empty()
@@ -430,12 +475,18 @@ class Kitchenlight:
 
     def empty(self):
         """ Set to mode "empty" and turn off Kitchenlight. """
+
         # Screen 0
         d = int(0).to_bytes(4, self._END)
         self._switch(d, poweroff=True)
 
     def checker(self, delay=500, colA="0000ff", colB="00ff00"):
-        """ Set to mode "checker". """
+        """ Set to mode "checker".
+            
+            delay = delay in ms (default 500)
+            colA = first color (default 0000ff)
+            colB = second color (default 00ff00) """
+
         # Kind of a hack: lets treat the two colors as DMX lights
         ca = Dmx("checker/a", colA.lstrip('#'))
         cb = Dmx("checker/b", colB.lstrip('#'))
@@ -456,7 +507,10 @@ class Kitchenlight:
         self._switch(d)
 
     def matrix(self, lines=8):
-        """ Set to mode "matrix". """
+        """ Set to mode "matrix".
+        
+            lines (>0, <32) = number of lines (default 8) """
+
         if int(lines) > 31: lines = 31 # Maximal line count
         d = bytearray(8)
         v = memoryview(d)
@@ -466,7 +520,10 @@ class Kitchenlight:
         self._switch(d)
 
     def moodlight(self, mode=1):
-        """ Set to mode "moodlight". """
+        """ Set to mode "moodlight".
+            
+            mode [1|2] = colorwheel(1) or random(2) """
+
         if mode == 1: # Mode "Colorwheel"
             d = bytearray(19)
             v = memoryview(d)
@@ -498,7 +555,10 @@ class Kitchenlight:
         self._switch(d)
 
     def openchaos(self, delay=1000):
-        """ Set to mode "openchaos". """
+        """ Set to mode "openchaos".
+        
+            delay = delay in milliseconds (default 1000) """
+
         d = bytearray(8)
         v = memoryview(d)
         # Screen 4
@@ -508,21 +568,27 @@ class Kitchenlight:
 
     def pacman(self):
         """ Set to mode "pacman". """
+
         # Screen 5
         d = int(5).to_bytes(4, self._END)
         self._switch(d)
 
     def sine(self):
         """ Set to mode "sine". """
+
         # Screen 6
         d = int(6).to_bytes(4, self._END)
         self._switch(d)
 
     # Screen 7 is Strobo, which is disabled because it seems to do harm to
-    # the Kitchenlight. Evil strobo!
+    # the Kitchenlight. Evil strobo.
 
     def text(self, text="Hello World", delay=250):
-        """ Set to mode "text". """
+        """ Set to mode "text".
+            
+            text (str < 256 bytes) = text to display (default "Hello World")
+            delay = delay in milliseconds (default 250) """
+
         text = text.encode("ascii", "ignore")
         if len(text) > 256: # Maximum text length
             print("Warning: text length must not exceed 256 characters!", file=sys.stderr)
@@ -739,15 +805,19 @@ class ColorScheme:
 
     def from_color(self, color):
         """ Derive ColorScheme from a single hex color. """
+
         self.single_color = color.lstrip('#').strip('-')
 
     def from_random(self):
         """ Derive ColorScheme from random colors. """
+
         self.return_random_color = True
 
     def list_available(self):
         """ List available presets. """
+
         import os
+
         cfg_dir = self._get_cfg_dir()
         if not cfg_dir:
             self.available = self._virtual_presets.copy()
@@ -763,6 +833,7 @@ class ColorScheme:
 
     def store(self, name):
         """ Store the current state of all lights as preset. """
+
         # First of all, refuse to override virtual presets
         if name in self._virtual_presets:
             print("I'm sorry Dave. I'm afraid I can't do that. The name \"{}\" is reserved. Please choose a different one.".format(name))
@@ -821,6 +892,7 @@ class ColorScheme:
                         else:
                             fd.write("{} = {}\n".format(topic, color))
 
+        # Do not close stdout
         if name != '-':
             fd.close()
             print("Wrote preset \"{}\"".format(name))
@@ -865,6 +937,7 @@ class RemotePresets:
 
     def _expand_room_name(self, name):
         """ Returns a valid room name expanded from the given name. """
+
         if name in self.map.keys():
             # Return on exact match
             return name
@@ -922,6 +995,7 @@ class RemotePresets:
 
     def query_available(self, rooms=["global"]):
         """ Returns a dict of remotely available presets for [rooms]. """
+
         import json
 
         # Presets in "global" are available everywhere and should always be included
@@ -1041,8 +1115,8 @@ if __name__ == "__main__":
         "-f", "--fnordcenter", type=str, dest="f_color", metavar="PRESET",
         help="apply local colorscheme PRESET to Fnordcenter")
     group_cl.add_argument(
-        "-M", "--magic", action="store_true",
-        help="Use fluffyd to change colors.")
+        "-m", "--magic", action="store_true",
+        help="use fluffyd to change colors")
     group_cl.add_argument(
         "-l", "--list-presets", action="store_true",
         help="list locally available presets")