1 //获取用户真实IP 
 2 
 3 function getIp() { 
 4 
 5     if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"),
 6  "unknown")) 
 7 
 8         $ip = getenv("HTTP_CLIENT_IP"); 
 9 
10     else 
11 
12         if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) 
13 
14             $ip = getenv("HTTP_X_FORWARDED_FOR"); 
15 
16         else 
17 
18             if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) 
19 
20                 $ip = getenv("REMOTE_ADDR"); 
21 
22             else 
23 
24                 if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && 
25 strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) 
26 
27                     $ip = $_SERVER['REMOTE_ADDR']; 
28 
29                 else 
30 
31                     $ip = "unknown"; 
32 
33     return ($ip); 
34 
35 }
36 
37 //使用方法如下
38 
39 echo getIp();