php 獲取調用接口服務器的公網IP

function getClientIp(){

if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'),'unknown')){
$onlineip = getenv('HTTP_CLIENT_IP');
}
elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'),'unknown')){
$onlineip = getenv('HTTP_X_FORWARDED_FOR');
}
elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'),'unknown')){
$onlineip = $_SERVER['REMOTE_ADDR'];
}
preg_match("/[\d\.]{7,15}/", $onlineip, $onlineipmatches);
$onlineip = $onlineipmatches[0] ? $onlineipmatches[0] : 'unknown';

return $onlineip;
}