外部呼叫JavaScript跟PHP(2) - 線上人數偵測－雜七雜八的kewang部落格

了解外部呼叫JavaScript跟PHP(1)之後，接下來就要做線上人數偵測。

參考了網站建置百寶箱的這篇文章之後，我們必須將程式碼的輸出部分修改為document.writeln的方式。

大家會發現我寫的第一篇文章，裡面用到一堆的echo還有document.writeln，因為太繁雜了，我們可以用function改寫，到時候如果有一大堆的document.writeln，我們只要直接呼叫print_by_js就可以了。



   function print_by_js($string)

   {

      echo "document.writeln(\"$string\");\n";

   }

在開發此功能時，需要建立兩個檔案ip.txt以及time.txt，權限均為666。下面就是我改寫網站建置百寶箱文章之後的原始碼，而且我多增加了一個功能，就是顯示你瀏覽此網站的IP。



<?php

   //treat the php file as javascript file

   Header("content-type: application/x-javascript");



   //call external javascript

   function print_by_js($string)

   {

      echo "document.writeln(\"$string\");\n";

   }



   //get time of day

   $now = gettimeofday();

   

   $filetime = file_get_contents('time.txt');



   //if time.txt is NULL, then write now['sec'] to time.txt and clear ip.txt

   if($filetime == '')

   {

      $f_time = fopen('time.txt', 'w+');

      fputs($f_time, $now['sec']);

      fclose($f_time);



      $f_ip=fopen('ip.txt', 'w+');

      fputs($f_ip, '');

      fclose($f_ip);

   }



   //get time of today

   $filetime = file_get_contents('time.txt');



   //refresh time is 60secs

   $threshold = ($now['sec'] - $filetime);



   //if refresh time is greater than 60secs, then clear time.txt

   if($threshold > 60)

   {

      $f_time = fopen('time.txt', 'w+');

      fputs($f_time, '');

      fclose($f_time);

   }



   //open ip.txt, its mode is "append"

   $f_ip = fopen('ip.txt', 'a+');



   //get remote address

   $ip = $_SERVER['REMOTE_ADDR'];



   $flag = 1;

   $fileip = file('ip.txt');

   $total = count($fileip);



   //exclusive the same IP

   for($i = 0; $i < $total; $i++)

   {

      if("$ip\n" == $fileip[$i])

      {

         $flag = 0;

         break;

      }

   }



   if($flag == 1)

   {

      $ipstring = "$ip\n";

      fputs($f_ip, $ipstring);

   }

   fclose($f_ip);



   //show onlines

   $fileip = file('ip.txt');

   $onlines = count($fileip);



   print_by_js("您的IP為$ip<br />");

   print_by_js("目前線上人數：$onlines");

?>