2012-10-01 33 views

Trả lời

5

mã sau này là một ví dụ làm thế nào để tạo ra một daemon sử dụng python trên Linux, nếu tôi không trả lời câu hỏi của bạn, bạn nên xem xét liên kết này http://ridingpython.blogspot.com.br/2011/08/turning-your-python-script-into-linux.html

main.py

import sys 
from daemon import Daemon 

class MyDaemon(Daemon): 
    def run(self): 
     print 'working' 

if __name__ == "__main__": 
    daemon = MyDaemon('/tmp/HMTd.pid') 
    if len(sys.argv) > 1: 
     if 'start' == sys.argv[1]: 
      daemon.start() 
     elif 'stop' == sys.argv[1]: 
      daemon.stop() 
     elif 'restart' == sys.argv[1]: 
      daemon.restart() 
     else: 
      print "Unknown command" 
      sys.exit(2) 
     sys.exit(0) 
    else: 
     print "usage: %s start|stop|restart" % sys.argv[0] 
     sys.exit(2) 

lớp daemon.py

import sys, os, time, atexit 
from signal import SIGTERM 

class Daemon: 
    """ 
    A generic daemon class. 

    Usage: subclass the Daemon class and override the run() method 
    """ 
    def __init__(self, pidfile, stdin='/dev/stdin', stdout='/dev/stdout', stderr='/dev/stderr'): 
     self.stdin = stdin 
     self.stdout = stdout 
     self.stderr = stderr 
     self.pidfile = pidfile 

    def daemonize(self): 
     """ 
     do the UNIX double-fork magic, see Stevens' "Advanced 
     Programming in the UNIX Environment" for details (ISBN 0201563177) 
     http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16 
     """ 
     try: 
      pid = os.fork() 
      if pid > 0: 
       # exit first parent 
       sys.exit(0) 
     except OSError, e: 
      sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror)) 
      sys.exit(1) 

     # decouple from parent environment 
     os.chdir("/") 
     os.setsid() 
     os.umask(0) 

     # do second fork 
     try: 
      pid = os.fork() 
      if pid > 0: 
       # exit from second parent 
       sys.exit(0) 
     except OSError, e: 
      sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror)) 
      sys.exit(1) 

     # redirect standard file descriptors 
     sys.stdout.flush() 
     sys.stderr.flush() 
     si = file(self.stdin, 'r') 
     so = file(self.stdout, 'a+') 
     se = file(self.stderr, 'a+', 0) 
     os.dup2(si.fileno(), sys.stdin.fileno()) 
     os.dup2(so.fileno(), sys.stdout.fileno()) 
     os.dup2(se.fileno(), sys.stderr.fileno()) 

     # write pidfile 
     atexit.register(self.delpid) 
     pid = str(os.getpid()) 
     file(self.pidfile,'w+').write("%s\n" % pid) 

    def delpid(self): 
     os.remove(self.pidfile) 

    def start(self): 
     """ 
     Start the daemon 
     """ 
     # Check for a pidfile to see if the daemon already runs 
     try: 
      pf = file(self.pidfile,'r') 
      pid = int(pf.read().strip()) 
      pf.close() 
     except IOError: 
      pid = None 

     if pid: 
      message = "pidfile %s already exist. Daemon already running?\n" 
      sys.stderr.write(message % self.pidfile) 
      sys.exit(1) 

     # Start the daemon 
     self.daemonize() 
     self.run() 

    def stop(self): 
     """ 
     Stop the daemon 
     """ 
     # Get the pid from the pidfile 
     try: 
      pf = file(self.pidfile,'r') 
      pid = int(pf.read().strip()) 
      pf.close() 
     except IOError: 
      pid = None 

     if not pid: 
      message = "pidfile %s does not exist. Daemon not running?\n" 
      sys.stderr.write(message % self.pidfile) 
      return # not an error in a restart 

     # Try killing the daemon process  
     try: 
      while 1: 
       os.kill(pid, SIGTERM) 
       time.sleep(0.1) 
     except OSError, err: 
      err = str(err) 
      if err.find("No such process") > 0: 
       if os.path.exists(self.pidfile): 
        os.remove(self.pidfile) 
      else: 
       print str(err) 
       sys.exit(1) 

    def restart(self): 
     """ 
     Restart the daemon 
     """ 
     self.stop() 
     self.start() 

    def run(self): 
     """ 
     You should override this method when you subclass Daemon. It will be called after the process has been 
     daemonized by start() or restart(). 
     """