php 守护进程（Daemon）

守护进程(daemon)是一类在后台运行的特殊进程，用于执行特定的系统任务。
很多守护进程在系统引导的时候启动，并且一直运行直到系统关闭。
守护进程一直在后台运行,脱离终端运行的程序独立运行的守护进程
  1 <?php
  2 class myProcess
  3 {
  4     const UID = 80;
  5     const GID = 80;
  6     protected $loop = true;
  7     protected $pidFile = "/tmp/myprocess.pid";
  8     //protected $data = "123132132
";
  9 
 10     private function checkPidFile()
 11     {
 12         if(file_exists($this->pidFile))
 13         {
 14             echo "daemon process is already runing.
";
 15             exit();
 16         }
 17     }
 18     private function daemon()
 19     {
 20     
 21         $pid = pcntl_fork();
 22         if ($pid == -1)
 23         {
 24             exit("fork fail");
 25         }else if($pid == 0){
 26             $this->handler();
 27         }else{
 28             exit();
 29         }
 30     }
 31 
 32     private function handler()
 33     {
 34         posix_setsid();
 35         posix_setuid(self::UID);
 36         posix_setgid(self::GID);
 37         #fclose(STDIN);  
 38         #fclose(STDOUT);  
 39         #fclose(STDERR); 
 40         #$pid = posix_getpid
 41         $pid = getmypid();
 42         file_put_contents($this->pidFile, $pid); #or die("open file fail");
 43     }
 44 
 45 
 46     private function start()
 47     {
 48         pcntl_signal_dispatch();
 49         $this->checkPidFile();
 50         $this->daemon();
 51         while ($this->loop) {
 52             $id = getmypid();
 53             //$f = fopen("/tmp/a.txt",a);
 54             //fwrite($f,$this->data);
 55             //file_put_contents("/tmp/".$id.".log","进程ID:$id 正常运行
");
 56             sleep(1);
 57         }
 58     }
 59 
 60     private function stop()
 61     {
 62         if (file_exists($this->pidFile)) {
 63            $pid = file_get_contents($this->pidFile);
 64            posix_kill($pid, SIGHUP);
 65            unlink($this->pidFile);
 66            echo "stop success.....";
 67         }else{
 68             echo "stop fail, daemon process not is already runing";
 69         }
 70     }
 71 
 72     private function restart()
 73     {
 74         $this->stop();
 75         $this->start();    
 76     }
 77 
 78     public function reload()
 79     {
 80         // $this->loop = false;
 81         // pcntl_signal_dispatch();
 82         // $this->loop = true;
 83         // $this->start();
 84     }
 85 
 86     public function main($argv)
 87     {
 88         switch ($argv[1]) {
 89              case 'start':
 90                $this->start();
 91                break;
 92              case 'stop':
 93                   $this->stop();
 94                   break;
 95             case 'restart':
 96                   $this->restart();
 97                   break;
 98             case 'reload':
 99                   $this->reload();
100                   break;
101              default: 
102                  echo 'php process.php start | stop | restart | reload';
103                  exit;
104         }
105     }
106 
107 }
108 
109 $proce = new myProcess();
110 $proce->main($argv);