synarere.py

   1 #!/usr/bin/env python
   2 #
   3 # synarere -- a highly modular and stable IRC bot.
   4 # Copyright (C) 2010 Michael Rodriguez.
   5 # Rights to this code are documented in docs/LICENSE.
   6
   7 '''Main program. This does basic routines, and calls core functions.'''
   8
   9 # Import required Python modules.
  10 import getopt, os, signal, sys
  11
  12 # Import required core modules.
  13 from core import module, irc, logger, io, var, confparse, command
  14
  15 # Import required core function.
  16 from core import shutdown
  17
  18 def ctcp_version(conn, (nick, user, host), message):
  19     '''Handle VERSION requests.'''
  20
  21     conn.sendq.appendleft('NOTICE %s :\001VERSION synarere-%s\001' % (nick, var.version))
  22     return
  23
  24 def ctcp_ping(conn, (nick, user, host), message):
  25     '''Handle PING requests.'''
  26
  27     conn.sendq.appendleft('NOTICE %s :\001PING %s\001' % (nick, message))
  28     return
  29
  30 def print_clo_help():
  31     '''Output command line options and their meanings.'''
  32
  33     print '-c (--config) <config>: Specify the configuration file to use.'
  34     print '-h (--help): Output this message.'
  35     print '-n (--nofork): Do not fork into the background (will output log messages)'
  36     print '-p (--pydebug): Start in the Python Debugger.'
  37     print '-v (--version): Output version information.'
  38
  39 def main(argv=sys.argv[1:]):
  40     '''Our entry point.'''
  41
  42     # Are we root?
  43     if os.geteuid() == 0:
  44         print >> sys.stderr, 'synarere: will not run as root for security reasons'
  45         sys.exit(0)
  46
  47     # Parse command line options and parameter list.
  48     try:
  49         opts, args = getopt.getopt(argv, 'c:hnpv', ['config=', 'help', 'nofork', 'pydebug', 'version'])
  50     except getopt.GetoptError, err:
  51         print >> sys.stderr, '%s\n' % err
  52         print_clo_help()
  53         sys.exit(os.EX_USAGE)
  54
  55     for opt, arg in opts:
  56         if opt in ('-c', '--config'):
  57             var.config_file = arg
  58         elif opt in ('-h', '--help'):
  59             print_clo_help()
  60             sys.exit(os.EX_OK)
  61         elif opt in ('-n', '--nofork'):
  62             var.fork = False
  63         elif opt in ('-p', '--pydebug'):
  64             import pdb
  65             pdb.set_trace()
  66         elif opt in ('-v', '--version'):
  67             print 'synarere: version %s' % var.version
  68             sys.exit(os.EX_OK)
  69
  70     # Attach signals to handlers.
  71     signal.signal(signal.SIGHUP, lambda h: var.conf.rehash(True))
  72     signal.signal(signal.SIGINT, lambda i: shutdown(signal.SIGINT, 'Caught SIGINT (terminal interrupt)'))
  73     signal.signal(signal.SIGTERM, lambda t: shutdown(signal.SIGTERM, 'Caught SIGTERM'))
  74     signal.signal(signal.SIGPIPE, signal.SIG_IGN)
  75     signal.signal(signal.SIGALRM, signal.SIG_IGN)
  76     signal.signal(signal.SIGCHLD, signal.SIG_IGN)
  77     signal.signal(signal.SIGWINCH, signal.SIG_IGN)
  78     signal.signal(signal.SIGTTIN, signal.SIG_IGN)
  79     signal.signal(signal.SIGTTOU, signal.SIG_IGN)
  80     signal.signal(signal.SIGTSTP, signal.SIG_IGN)
  81
  82     print 'synarere: version %s' % var.version
  83
  84     # Initialize the configuration parser.
  85     try:
  86         var.conf = confparse.ConfigParser(var.config_file)
  87     except confparse.Exception, errstr:
  88         print >> sys.stderr, 'synarere: configuration error for %s: %s' % (var.config_file, errstr)
  89         sys.exit(os.EX_CONFIG)
  90
  91     # Check to see if we are already running.
  92     try:
  93         pid_file = open(var.conf.get('options', 'pidfile')[0], 'r')
  94
  95         try:
  96             pid = pid_file.read()
  97
  98             if pid:
  99                 pid = int(pid)
 100
 101                 try:
 102                     os.kill(pid, 0)
 103                 except OSError:
 104                     pass
 105
 106                 print >> sys.stderr, 'synarere: an instance is already running'
 107                 sys.exit(os.EX_SOFTWARE)
 108         finally:
 109             pid_file.close()
 110     except IOError:
 111         pass
 112
 113     # Fork into the background.
 114     if var.fork:
 115         try:
 116             pid = os.fork()
 117         except OSError, e:
 118             return (e.errno, e.strerror)
 119
 120         # This is the child process.
 121         if pid == 0:
 122             os.setsid()
 123
 124             # Now the child fork()'s a child in order to prevent acquisition
 125             # of a controlling terminal.
 126             try:
 127                 pid = os.fork()
 128             except OSError, e:
 129                 return (e.errno, e.strerror)
 130
 131             # This is the second child process.
 132             if pid == 0:
 133                 os.chdir(os.getcwd())
 134                 os.umask(0)
 135
 136             # This is the first child.
 137             else:
 138                 print 'synarere: pid', pid
 139                 print 'synarere: running in background mode from:', os.getcwd()
 140                 os._exit(0)
 141         else:
 142             os._exit(0)
 143
 144         # Try to write the PID file.
 145         try:
 146             pid_file = open(var.conf.get('options', 'pidfile')[0], 'w')
 147             pid_file.write(str(os.getpid()))
 148             pid_file.close()
 149         except IOError, e:
 150             print >> sys.stderr, 'synarere: unable to write pid file:', os.strerror(e.args[0])
 151
 152         # Try to close all open file descriptors.
 153         # If we cant find the max number, just close the first 256.
 154         try:
 155             maxfd = os.sysconf('SC_OPEN_MAX')
 156         except (AttributeError, ValueError):
 157             maxfd = 256
 158
 159         for fd in range(0, maxfd):
 160             try:
 161                 os.close(fd)
 162             except OSError:
 163                 pass
 164
 165         # Redirect the standard file descriptors to /dev/null.
 166         os.open('/dev/null', os.O_RDONLY)
 167         os.open('/dev/null', os.O_RDWR)
 168         os.open('/dev/null', os.O_RDWR)
 169     else:
 170         print 'synarere: pid', os.getpid()
 171         print 'synarere: running in foreground mode from:', os.getcwd()
 172
 173     # Initialize the logger.
 174     logger.init()
 175
 176     # These have to be in the main file.
 177     command.add('VERSION', ctcp_version, command.ctcp)
 178     command.add('PING', ctcp_ping, command.ctcp)
 179
 180     # Load all modules listed in the configuration.
 181     module.load_all()
 182
 183     # Connect to all IRC networks.
 184     irc.connect_to_all()
 185
 186     # Start the loop.
 187     io.io()
 188
 189     # This should NEVER happen.
 190     shutdown(os.EX_SOFTWARE, 'Main loop exited (?)')
 191
 192 if __name__ == '__main__':
 193     main()