<?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 OK

         Content-Length: 15

         Content-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();

 ?>