php获取客户端IP，并且可以返回IP所在地

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;
}

$ipInfos = GetIpLookup('123.125.114.144'); //baidu.com IP地址
var_dump($ipInfos);