Get IP from DNS without using gethostbyname?

问题

PHP's gethostbyname() function doesn't seem to be configurable as far as timeouts are concerned. I want to limit DNS requests to 1 second or less as anymore shows a problem and should be ignored.

So, is there a way to make a DNS query using sockets or cURL instead? I was able to make SMTP requests using PHP streams which saved server resources, so I'm looking to do the same with DNS queries.

回答1:

The comments on the PHP article have some options for setting/including a timeout:

<?php
function getAddrByHost($host, $timeout = 3) {
   $query = `nslookup -timeout=$timeout -retry=1 $host`;
   if(preg_match('/\nAddress: (.*)\n/', $query, $matches))
      return trim($matches[1]);
   return $host;
}
?>

http://www.php.net/manual/en/function.gethostbyname.php#92870

来源：https://stackoverflow.com/questions/4305604/get-ip-from-dns-without-using-gethostbyname