ServiceBot: make displaying unknown command errors optional

Closes #441.

example-conf.yml

@@ -68,6 +68,9 @@ pylink:
     #plugin_dirs: ["~/my-plugins", "~/pylink-contrib-modules/plugins"]
     #protocol_dirs: ["~/pylink-contrib-modules/protocols"]
 
+    # Determines whether we should show unknown command errors for service bots. Defaults to True.
+    #show_unknown_commands: true
+
 login:
     # NOTE: for users migrating from PyLink < 1.1, the old login:user/login:password settings
     # have been deprecated. We strongly recommend migrating to the new "accounts:" block below, as
@@ -685,6 +688,10 @@ automode:
     # block.
     #respond_to_nick: true
 
+    # Determines whether we should show unknown command errors for this service bot. Defaults to True.
+    # This overrides the "show_unknown_commands" option in the "pylink:" config block.
+    #show_unknown_commands: true
+
 games:
     # Sets the nick of the Games service, if you're using it. This defaults to "games" if not defined.
     nick: Games

utils.py

@@ -335,7 +335,12 @@ class ServiceBot():
         cmd = cmd_args[0].lower()
         cmd_args = cmd_args[1:]
         if cmd not in self.commands:
-            if cmd and not cmd.startswith('\x01'):
+            # XXX: we really need abstraction for this kind of config fetching...
+            show_unknown_cmds = irc.serverdata.get('%s_show_unknown_commands' % self.name,
+                                                   conf.conf.get(self.name, {}).get('show_unknown_commands',
+                                                   conf.conf['pylink'].get('show_unknown_commands', True)))
+
+            if cmd and show_unknown_cmds and not cmd.startswith('\x01'):
                 # Ignore empty commands and invalid command errors from CTCPs.
                 self.reply(irc, 'Error: Unknown command %r.' % cmd)
             log.info('(%s/%s) Received unknown command %r from %s', irc.name, self.name, cmd, irc.getHostmask(source))