如何从访客获得真实IP？

Question

我正在使用以下PHP代码获取访问者的IP地址：

<?php echo $_SERVER['REMOTE_ADDR']; ?>

但是，当访客使用Proxy时，我无法从访客那里获得真实的IP地址。在这种情况下，是否可以获取访客的IP地址？

Answer 1

这是我见过的最常见的技术：function getUserIP() {&nbsp; &nbsp; if( array_key_exists('HTTP_X_FORWARDED_FOR', $_SERVER) && !empty($_SERVER['HTTP_X_FORWARDED_FOR']) ) {&nbsp; &nbsp; &nbsp; &nbsp; if (strpos($_SERVER['HTTP_X_FORWARDED_FOR'], ',')>0) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $addr = explode(",",$_SERVER['HTTP_X_FORWARDED_FOR']);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return trim($addr[0]);&nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return $_SERVER['HTTP_X_FORWARDED_FOR'];&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; else {&nbsp; &nbsp; &nbsp; &nbsp; return $_SERVER['REMOTE_ADDR'];&nbsp; &nbsp; }}请注意，这并不保证您将始终获得正确的用户IP，因为有很多隐藏它的方法。

Answer 2

这是我的方法：&nbsp;function getRealUserIp(){&nbsp; &nbsp; switch(true){&nbsp; &nbsp; &nbsp; case (!empty($_SERVER['HTTP_X_REAL_IP'])) : return $_SERVER['HTTP_X_REAL_IP'];&nbsp; &nbsp; &nbsp; case (!empty($_SERVER['HTTP_CLIENT_IP'])) : return $_SERVER['HTTP_CLIENT_IP'];&nbsp; &nbsp; &nbsp; case (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) : return $_SERVER['HTTP_X_FORWARDED_FOR'];&nbsp; &nbsp; &nbsp; default : return $_SERVER['REMOTE_ADDR'];&nbsp; &nbsp; }&nbsp;}如何使用：$ip = getRealUserIp();