Domain to IP : If anyone knew how to do this I would be impressed!!

lch_hosting

Hi,
Anyone know how to code a PHP script to do the following?:

Ok say a client enters a domain does anyone know a way to check what IP the domain resolves to? So for example if a client enters say “domain.com” the script would query a whois database or some how ping it and the result would be something like $result=<ip domain resolves to>? Anyone know how to do this if you did I would be quite impressed - thanks for any help you can offer!!

adamgeorge

It's not that hard. You need to learn how to make socket connections to a website, and post data to them. The website will reply and send you back the relevant information.

Here's how:

Make a socket connection to http://www.dnsstuff.com or other lookup site.
If you look at dnsstuff.com there is a form on there that lets you do lookups. View the source on that page. Note down the URL the form submits to, and the names off all the variables in the form.
In php using the socket connection you created, send a post header (using fput()) with relevant data you jotted down from the form, to the URL the form submits to. Basically you are doing here what your webbrowser does here when you fill in a form.
Use fget() to retrive the data the server sends back in response. You will then need to use a regular expression to extract what you need from the data. The server will just send back HTML so you will need to use a regular expression to get what you want. It shouldn't be too tricky.

And that's about it. I'll leave it up to you to go about implementing it. Have a go. If you get really stuck I'll post some code to get you started.

Just read php documentation on the following functions and you should be right:

fsockopen()
fput()
fget()

those three function will allow you to comunicate with another website from php.

Good luck
-Adam 🙂

ir4z0r

<?PHP

  echo "Domain's IP is: " . gethostbyname($_POST['hostname']);
  echo "Domainname is: " . gethostbyaddr($_POST['ip']);

?>

what about that, that's does the trick, doesn't it?

adamgeorge

hehe.

That's pretty funny. I didn't even know there was a such functions in php.

Still... if you're really bored and want to learn how to make socket connections you could still it that way lol.

cya man
-Adam 🙂

laserlight

the function should be gethostbyname(), though some guy commenting on php.net notes that sometimes the function may take a fair bit of time to process so it presumably should be used sparingly.

edwardsbc

Actually, it looks like Adams reply is more likey to solve lch_hosting's problem. He is asking to find the IP of a domain the client provided, not the IP/hostname of the client's browser.

If you are using a linux box as your host you can always use 'dig' (and thus the local bind libraries) to find if a SOA record exists in the DNS heirarchy. The output of dig is easily parsed and can be returned using PHP's system shell functions.

I'm not sure you can easily determine the IP range assigned to the DOMAIN. You can determine the IP of an actual HOST (subtle difference).

ir4z0r

what gives you the idea, these functions return the client's IP/hostname?

gethostbyaddr
Get the Internet host name corresponding to a given IP address

gethostbyname
Get the IP address corresponding to a given Internet host name

cyclops

what if the domain is on a round robin DNS ?
chances are that you will get a different IP every X minutes

superwormy

I second ir4z0r, he has the best solution. edwardsbc is confused.