<?php
$url = "http://csdn.net/index.php?cn8=cn8-0a13AQQAC7";
$ch = curl_init();
curl_setopt ($ch, CURLOPT_URL, $url);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT,10);
$dxycontent = curl_exec($ch);
echo $dxycontent;
?>
请问php的$url获取当前域名怎么写?不写域名的话,怎么获取当前域名?