遇到一超难问题，用php怎么获取远程调用者ip，内详，高手进

Question

http://expert.csdn.net/Expert/FAQ/FAQ_Index.asp?id=19325

Answer 1

PHP中怎样来访获得IP地址?  
---------------------------------------------------------------  
 
<?//补充一下，有时候$REMOTE_ADDR;并不一定是你真是的ip  
//用HTTP_X_FORWARDED_FOR更真实一些  
if  (getenv(HTTP_X_FORWARDED_FOR))  {  
$ip  =  getenv('HTTP_X_FORWARD_FOR');  
$host  =  gethostbyaddr($ip);  
}  else  {  
$ip  =  getenv('REMOTE_ADDR');  
$host  =  gethostbyaddr($ip);  
}?>  
---------------------------------------------------------------  
 
echo  gethostbyname("www.csdn.net")."<br>"  
---------------------------------------------------------------  
 
                       //  取得客户IP  
                       function  get_client_ip()    
                       {  
                                   global  $_SERVER;  
                                   if  (isset($_SERVER["HTTP_X_FORWARDED_FOR"]))    
                                   {  
                                               $realip  =  $_SERVER["HTTP_X_FORWARDED_FOR"];  
                                   }  
                                   elseif  (isset($_SERVER["HTTP_CLIENT_IP"]))    
                                   {  
                                               $realip  =  $_SERVER["HTTP_CLIENT_IP"];  
                                   }  
                                   else    
                                   {  
                                               $realip  =  $_SERVER["REMOTE_ADDR"];  
                                   }  
                                   return  $realip;              
                       }  
---------------------------------------------------------------  
 
好象都很全面啊。  
简单点  getenv('REMOTE_ADDR');