<?php //Accpet the http client request and generate response content.//As a demo, this function just send "PHP HTTP Server" to client.function handle_http_request($address, $port){  $max_backlog = 16;  $res_content = "HTTP/1.1 200 OKContent-Length: 15Content-Type: text/plain; charset=UTF-8 PHP HTTP Server";  $res_len = strlen($res_content);   //Create, bind and listen to socket  if(($socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === FALSE)  {    echo "Create socket failed!/n";    exit;  }     if((socket_bind($socket, $address, $port)) === FALSE)  {    echo "Bind socket failed!/n";    exit;  }     if((socket_listen($socket, $max_backlog)) === FALSE)  {    echo "Listen to socket failed!/n";    exit;  }   //Loop  while(TRUE)  {    if(($accept_socket = socket_accept($socket)) === FALSE)    {      continue;    }    else    {      socket_write($accept_socket, $res_content, $res_len);        socket_close($accept_socket);    }  }} //Run as daemon process.function run(){  if(($pid1 = pcntl_fork()) === 0)  //First child process  {    posix_setsid(); //Set first child process as the session leader.         if(($pid2 = pcntl_fork()) === 0)    //Second child process, which run as daemon.    {      //Replaced with your own domain or address.      handle_http_request('www.codinglabs.org', 9999);     }    else    {      //First child process exit;      exit;    }  }  else  {    //Wait for first child process exit;    pcntl_wait($status);  }} //Entry point.run(); ?>