--- a/rollbot.py	Wed May 11 00:04:29 2016 +0800
+++ b/rollbot.py	Wed May 11 00:06:30 2016 +0800
@@ -15,11 +15,11 @@
 
 
 class RollBot(sleekxmpp.ClientXMPP):
-    def __init__(self, jid, password, nick):
+    def __init__(self, jid, password, nick, prefix):
         sleekxmpp.ClientXMPP.__init__(self, jid, password)
 
         self.nick = nick
-        self.prefix = '!'
+        self.prefix = prefix
         self.commands = []
 
         self.add_event_handler('session_start', self.start)
@@ -94,6 +94,7 @@
     group.add_argument('-j', '--jid', help='JID to use')
     group.add_argument('-p', '--password', help='password to use')
     group.add_argument('-n', '--nick', help='MUC nickname')
+    group.add_argument('--prefix', help='command prefix (default: !)')
 
     group = parser.add_mutually_exclusive_group()
     group.add_argument('-q', '--quiet', help='set logging to ERROR', action='store_const', dest='loglevel', const=logging.ERROR, default=logging.INFO)
@@ -111,8 +112,9 @@
     jid = lookup('jid', args, config)
     password = lookup('password', args, config)
     nick = lookup('nick', args, config, default='rollbot')
+    prefix = lookup('prefix', args, config, default='!')
 
-    rollbot = RollBot(jid, password, nick)
+    rollbot = RollBot(jid, password, nick, prefix)
     rollbot.auto_authorize = True
     rollbot.auto_subscribe = True
     rollbot.register_plugin('xep_0030') # Service Discovery