php实现统计网站在线人数的方法

本文实例讲述了php实现统计网站在线人数的方法。分享给大家供大家参考。具体实现方法如下：

    <?php
    function getIpAddress() { // 取得当前用户的IP地址
     if (getenv('HTTP_CLIENT_IP')) {
     $ip = getenv('HTTP_CLIENT_IP');
     } elseif (getenv('HTTP_X_FORWARDED_FOR')) {
     $ip = getenv('HTTP_X_FORWARDED_FOR');
     } elseif (getenv('REMOTE_ADDR')) {
     $ip = getenv('REMOTE_ADDR');
     } else {
     $ip = $_SERVER['REMOE_ADDR'];
     } 
     return $ip;
    } 
    function writeover($filename,$data,$method = 'w',$chmod = 0){
     $handle = fopen($filename, $method);
     !handle && die("文件打开失败");
     flock($handle, LOCK_EX);
     fwrite($handle, $data);
     flock($handle, LOCK_UN);
     fclose($handle);
     $chmod && @chmod($filename, 0777);
    } 
    function count_online_num($time, $ip) {
     $fileCount = './count.txt';
     $count = 0;
     $gap = 900; //15分钟不刷新页面就
     if (!file_exists($fileCount)) {
     $str = $time . "\t" . $ip . "\r\n";
     writeover($fileCount, $str, 'w', 1);
     $count = 1;
     } else {
     $arr = file($fileCount);
     $flag = 0;
     foreach($arr as $key => $val) {
      $val= trim($val);
      if ($val != "") {
      list($when, $seti) = explode("\t", $val);
      if ($seti ==$ip) {
       $arr[$key] = $time . "\t" . $seti;
       $flag = 1;
      } else {
       $currentTime = time();
       if ($currentTime - $when > 900) {
       unset($arr[$key]);
       }else{
       $arr[$key]=$val;
       }
      } 
      } 
     } 
     if ($flag == 0) {
      array_push($arr, $time . "\t" . $ip);
     } 
     $count = count($arr);
     $str = implode("\r\n", $arr);
     $str.="\r\n";
     writeover($fileCount, $str, 'w', 0);
     unset($arr);
     } 
     return $count;
    } 
    $time = time();
    $ip = getIpAddress();
    $online_num = count_online_num($time,$ip);
    echo $online_num;
    ?>

希望本文所述对大家的php程序设计有所帮助。