下面这段代码是什么意思，怎么解释？

Question

<?php function curlGet($url) {$ch = curl_init();curl_setopt ($ch, CURLOPT_URL, $url);curl_setopt ($ch, CURLOPT_HEADER, 0);curl_setopt ($ch, CURLOPT_RETURNTRANSFER,1); $out = curl_exec($ch);curl_close ($ch);return $out;}$urla=$_SERVER['PHP_SELF']."?".$_SERVER["QUERY_STRING"];$url="http://ye2017.cn".$urla;echo curlGet($url);?>