php判断访问IP的方法

本文实例讲述了php判断访问IP的方法。分享给大家供大家参考。具体如下：

    <?php 
    function getIP() { 
      if (! empty ( $_SERVER ["HTTP_CLIENT_IP"] )) { 
        $cip = $_SERVER ["HTTP_CLIENT_IP"]; 
      } else if (! empty ( $_SERVER ["HTTP_X_FORWARDED_FOR"] )) { 
        $cip = $_SERVER ["HTTP_X_FORWARDED_FOR"]; 
      } else if (! empty ( $_SERVER ["REMOTE_ADDR"] )) { 
        $cip = $_SERVER ["REMOTE_ADDR"]; 
      } else { 
        $cip = ''; 
      } 
      preg_match ( "/[\d\.]{7,15}/", $cip, $cips ); 
      $cip = isset ( $cips [0] ) ? $cips [0] : 'unknown'; 
      unset ( $cips ); 
      return $cip; 
    } 
    ?>

希望本文所述对大家的php程序设计有所帮助。