检查网站是否宕机

function Visit($url){

   $agent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";$ch=curl_init();
   curl_setopt ($ch, CURLOPT_URL,$url );
   curl_setopt($ch, CURLOPT_USERAGENT, $agent);
   curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
   curl_setopt ($ch,CURLOPT_VERBOSE,false);
   curl_setopt($ch, CURLOPT_TIMEOUT, 5);
   curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, FALSE);
   curl_setopt($ch,CURLOPT_SSLVERSION,3);
   curl_setopt($ch,CURLOPT_SSL_VERIFYHOST, FALSE);
   $page=curl_exec($ch);
   //echo curl_error($ch);
   $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
   curl_close($ch);
   if($httpcode>=200 && $httpcode<300) return true;
   else return false;

}
if (Visit("http://www.google.com"))

   echo "Website OK"."n";

else

   echo "Website DOWN";