PHP 根据IP地址获取所在城市

<?php  
header('Content-Type:text/html;Charset=utf-8');  
 
 
function GetIp(){  
    $realip = '';  
    $unknown = 'unknown';  
    if (isset($_SERVER)){  
        if(isset($_SERVER['HTTP_X_FORWARDED_FOR']) && !empty($_SERVER['HTTP_X_FORWARDED_FOR']) && strcasecmp($_SERVER['HTTP_X_FORWARDED_FOR'], $unknown)){  
            $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);  
            foreach($arr as $ip){  
                $ip = trim($ip);  
                if ($ip != 'unknown'){  
                    $realip = $ip;  
                    break;  
                }  
            }  
        }else if(isset($_SERVER['HTTP_CLIENT_IP']) && !empty($_SERVER['HTTP_CLIENT_IP']) && strcasecmp($_SERVER['HTTP_CLIENT_IP'], $unknown)){  
            $realip = $_SERVER['HTTP_CLIENT_IP'];  
        }else if(isset($_SERVER['REMOTE_ADDR']) && !empty($_SERVER['REMOTE_ADDR']) && strcasecmp($_SERVER['REMOTE_ADDR'], $unknown)){  
            $realip = $_SERVER['REMOTE_ADDR'];  
        }else{  
            $realip = $unknown;  
        }  
    }else{  
        if(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), $unknown)){  
            $realip = getenv("HTTP_X_FORWARDED_FOR");  
        }else if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), $unknown)){  
            $realip = getenv("HTTP_CLIENT_IP");  
        }else if(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), $unknown)){  
            $realip = getenv("REMOTE_ADDR");  
        }else{  
            $realip = $unknown;  
        }  
    }  
    $realip = preg_match("/[\d\.]{7,15}/", $realip, $matches) ? $matches[0] : $unknown;  
    return $realip;  
}  
   
function GetIpLookup($ip = ''){  
    if(empty($ip)){  
        $ip = GetIp();  
    }  
    $res = @file_get_contents('http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js&ip=' . $ip);  
    if(empty($res)){ return false; }  
    $jsonMatches = array();  
    preg_match('#\{.+?\}#', $res, $jsonMatches);  
    if(!isset($jsonMatches[0])){ return false; }  
    $json = json_decode($jsonMatches[0], true);  
    if(isset($json['ret']) && $json['ret'] == 1){  
        $json['ip'] = $ip;  
        unset($json['ret']);  
    }else{  
        return false;  
    }  
    return $json;  
}  
$ip = GetIp();
 
  
 
$ipInfos = GetIpLookup($ip); //baidu.com IP地址  