php获取客户端来源的ip，代码如下：

 1     function getIP()
2     {
3         if (isset($_SERVER)) {
4             if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
5                 $realip = $_SERVER['HTTP_X_FORWARDED_FOR'];
6             } elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
7                 $realip = $_SERVER['HTTP_CLIENT_IP'];
8             } else {
9                 $realip = $_SERVER['REMOTE_ADDR'];
10             }
11         } else {
12             if (getenv("HTTP_X_FORWARDED_FOR")) {
13                 $realip = getenv( "HTTP_X_FORWARDED_FOR");
14             } elseif (getenv("HTTP_CLIENT_IP")) {
15                 $realip = getenv("HTTP_CLIENT_IP");
16             } else {
17                 $realip = getenv("REMOTE_ADDR");
18             }
19         }
20         return $realip;
21     }