<?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();
 
?>