diff --git a/kitchentext.py b/kitchentext.py
index 5b05e1b..33ae252 100755
--- a/kitchentext.py
+++ b/kitchentext.py
@@ -1,39 +1,33 @@
 #!/usr/bin/env python3
 #
 # kitchentext: Read text from stdin and put it on the Kitchenlight.
+#
+# Author: Shy
 
-def kitchentext(delay=200, single=False, wait=False, restore=False, poweron=False,
-        verbose=False, debug=False):
+def kitchentext(delay=200, single=False, wait=False, restore=False,
+                poweron=False, verbose=False, debug=False):
 
     import sys
     from c4ctrl import C4Interface, Kitchenlight
 
     charwidth = { # Width of characters.
-        'a' : 5, 'A' : 5, 'b' : 4, 'B' : 5,
-        'c' : 3, 'C' : 5, 'd' : 4, 'D' : 5,
-        'e' : 4, 'E' : 5, 'f' : 3, 'F' : 5,
-        'g' : 3, 'G' : 5, 'h' : 3, 'H' : 5,
-        'i' : 1, 'I' : 5, 'j' : 2, 'J' : 5,
-        'k' : 3, 'K' : 5, 'l' : 3, 'L' : 5,
-        'm' : 5, 'M' : 5, 'n' : 4, 'N' : 5,
-        'o' : 3, 'O' : 5, 'p' : 3, 'P' : 5,
-        'q' : 3, 'Q' : 5, 'r' : 3, 'R' : 5,
-        's' : 4, 'S' : 5, 't' : 3, 'T' : 5,
-        'u' : 3, 'U' : 5, 'v' : 3, 'V' : 5,
-        'w' : 5, 'W' : 5, 'x' : 3, 'X' : 5,
-        'y' : 3, 'Y' : 5, 'z' : 3, 'Z' : 5,
-        '0' : 5, '1' : 4, '2' : 5, '3' : 5,
-        '4' : 5, '5' : 5, '6' : 5, '7' : 5,
-        '8' : 5, '9' : 5, '@' : 5, '=' : 3,
-        '!' : 1, '"' : 3, '_' : 5, '-' : 3,
-        '.' : 2, ',' : 2, '*' : 5, ':' : 2,
-        '\'' : 1, '/' : 5, '(' : 2, ')' : 2,
-        '{' : 3, '}' : 3, '[' : 2, ']' : 2,
-        '<' : 3, '>' : 4, '+' : 5, '#' : 5,
-        '$' : 5, '%' : 5, '$' : 5, '~' : 5,
-        '?' : 3, ';' : 2, '\\' : 5, '^' : 3,
-        '|' : 1, '`' : 2, ' ' : 3, '\t' : 5
-        }
+        'a' : 5, 'A' : 5, 'b' : 4, 'B' : 5, 'c' : 3, 'C' : 5,
+        'd' : 4, 'D' : 5, 'e' : 4, 'E' : 5, 'f' : 3, 'F' : 5,
+        'g' : 3, 'G' : 5, 'h' : 3, 'H' : 5, 'i' : 1, 'I' : 5,
+        'j' : 2, 'J' : 5, 'k' : 3, 'K' : 5, 'l' : 3, 'L' : 5,
+        'm' : 5, 'M' : 5, 'n' : 4, 'N' : 5, 'o' : 3, 'O' : 5,
+        'p' : 3, 'P' : 5, 'q' : 3, 'Q' : 5, 'r' : 3, 'R' : 5,
+        's' : 4, 'S' : 5, 't' : 3, 'T' : 5, 'u' : 3, 'U' : 5,
+        'v' : 3, 'V' : 5, 'w' : 5, 'W' : 5, 'x' : 3, 'X' : 5,
+        'y' : 3, 'Y' : 5, 'z' : 3, 'Z' : 5, '0' : 5, '1' : 4,
+        '2' : 5, '3' : 5, '4' : 5, '5' : 5, '6' : 5, '7' : 5,
+        '8' : 5, '9' : 5, '@' : 5, '=' : 3, '!' : 1, '"' : 3,
+        '_' : 5, '-' : 3, '.' : 2, ',' : 2, '*' : 5, ':' : 2,
+        '\'' : 1, '/' : 5, '(' : 2, ')' : 2, '{' : 3, '}' : 3,
+        '[' : 2, ']' : 2, '<' : 3, '>' : 4, '+' : 5, '#' : 5,
+        '$' : 5, '%' : 5, '$' : 5, '~' : 5, '?' : 3, ';' : 2,
+        '\\' : 5, '^' : 3, '|' : 1, '`' : 2, ' ' : 3, '\t' : 5
+    }
 
     C4Interface.debug = debug
     kl = Kitchenlight(autopower=poweron)
@@ -44,7 +38,7 @@ def kitchentext(delay=200, single=False, wait=False, restore=False, poweron=Fals
     # Store previous state.
     if restore:
         c4 = C4Interface()
-        safe = c4.pull([kl.topic, kl.powertopic])
+        saved_state = c4.pull([kl.topic, kl.powertopic])
 
     try:
         while True:
@@ -52,7 +46,7 @@ def kitchentext(delay=200, single=False, wait=False, restore=False, poweron=Fals
             try:
                 text = sys.stdin.readline()
             except KeyboardInterrupt: # Exit a bit more graceful on CTRL-C.
-                verbose and sys.stderr.write("\rInterrupted by user\n")
+                verbose and print("\nInterrupted by user.", file=sys.stderr)
                 sys.exit(1)
 
             if single and text.rstrip('\n') == "":
@@ -73,27 +67,28 @@ def kitchentext(delay=200, single=False, wait=False, restore=False, poweron=Fals
                 if wait:
                     from time import sleep
                     # How long shall we wait?
-                    # Kitchenlight has 30 columns, each char uses 2-5 columns followed by an empty
-                    # one. The traversal of one column takes 30 * <delay> ms.
+                    # Kitchenlight has 30 columns, each char uses 2-5 columns
+                    # followed by an empty one. The traversal of one column
+                    # takes 30 * <delay> ms.
                     twidth = 0
                     for c in text:
                         try:
                             twidth += (charwidth[c] + 1)
                         except KeyError:
                             twidth += 4 # Fallback
-                    wait_for = ((30 * delay) + (twidth * delay))/1000
+                    wait_for = ((30 * delay) + (twidth * delay)) / 1000
                     verbose and print("Waiting for {} seconds ...".format(wait_for))
                     sleep(wait_for)
 
             except KeyboardInterrupt:
-                verbose and sys.stderr.write("\rInterrupted by user\n")
+                verbose and print("\nInterrupted by user.", file=sys.stderr)
                 sys.exit(1)
 
     finally:
         # Always restore privious state if "restore" is set.
         if restore:
             re = []
-            for top in safe: re.append((top.topic, top.payload))
+            for top in saved_state: re.append((top.topic, top.payload))
             c4.push(re)
 
 
@@ -113,7 +108,8 @@ if __name__ == "__main__":
         help="wait until the text has been displayed")
     parser.add_argument(
         "-r", "--restore", action="store_true", default=False,
-        help="restore the Kitchenlight to its prior state after the text has been displayed (implies --wait)")
+        help="restore the Kitchenlight to its prior state after the text has \
+              been displayed (implies --wait)")
     parser.add_argument(
         "-p", "--power-on", action="store_true", default=False,
         help="turn on Kitchenlight if it is powered off")
@@ -125,13 +121,19 @@ if __name__ == "__main__":
         help="be (not much) more verbose")
     parser.add_argument(
         "--debug", action="store_true",
-        help="display what would be send to the MQTT broker, but do not actually connect")
+        help="display what would be send to the MQTT broker, but do not \
+              actually connect")
     args = parser.parse_args()
 
     if args.fork:
         import sys
         from posix import fork
 
+        if sys.stdin.isatty():
+            print("Error: cannot fork when stdin is connected to a terminal!",
+                  file=sys.stderr)
+            sys.exit(1)
+
         child_pid = fork()
         if child_pid != 0:
             args.verbose and print("Forked to PID", child_pid)