Python实现通用的unix/linux守护进程，python守护进程,下面是一个守护进程的类，

Python实现通用的unix/linux守护进程，python守护进程,下面是一个守护进程的类，

下面是一个守护进程的类，要创建守护进程只需要继承此类，并实现run()方法.

此程序适用于 python2.x

#!/usr/bin/env pythonimport sys, os, time, atexitfrom signal import SIGTERMclass Daemon:        """        A generic daemon class.        Usage: subclass the Daemon class and override the run() method        """        def __init__(self, pidfile, stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):                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().                """

下面是一个实现，你可以通过start，stop或者restart参数控制守护进程的启动，停止和重启

#!/usr/bin/env pythonimport sys, timefrom daemon import Daemonclass MyDaemon(Daemon):        def run(self):                while True:                        time.sleep(1)if __name__ == "__main__":        daemon = MyDaemon('/tmp/daemon-example.pid')        if len(sys.argv) == 2:                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)

就是这样了，希望对大家有帮助.

本文转载自：http://www.jejik.com/articles/2007/02/a_simple_unix_linux_daemon_in_python/