domain checker how to do suggestions? - php

Question

I have a basic domain checker that returns a 'this domain is free' or 'this domain is not available' message. But how do I make suggestions?
Lets say the visitor checks whether 'www.stackoverflow.com' is available. When it's available, there's no problem and the user can go order it. When it's not available, i want it to do suggestions for other extensions. Like:
www.stackoverflow.com is not available,
The following domains are available:
www.stackoverflow.net
www.stackoverflow.co.uk
www.stackoverflow.info
This is my current file:
<?php
if(isset($_POST['check'])) {
if (!empty($_POST['domain_name'])){
$domain = trim($_POST['domein_naam']).$_POST['domain_list'];
$result = #dns_get_record($domain, DNS_ALL);
if(empty($result)) {
echo "<H2 style='color:green;' >Domain $domain is available.</H2>";
} else {
echo "<H2 style='color:red;'>Domain $domain is not available.</H2>";
}
} else {
echo "<H2 style='color:red;'>Fout: Domein kan niet leeg zijn.</H2>";
}
}
?>

Answer 1

Without knowing all of your code structure it's hard to give you the best method.
But a simple idea:
Say the site the user entered ($_POST/$_GET/etc) is stored in $strUserSite variable.
Have an array ($aryFurtherChecks or whatever) with all extensions in (.com, .net, etc).
Loop the array checking if each domain for what user entered is avail or not, by appending your $strUserSite var to it.
If domain + extension from array is available, either echo it out (depending on your code setup/framework etc) or add to new array, then loop second array with "These are also available".
Which methods you use depend on if you're using procedural all-in-one-file code, or classes etc.
If the latter then setting a new array would be preferred, looping it in your view/template/whatever file and echoing out each one with your HTML and styling etc.

Answer 2

dns_get_record() cannot be used to determine whether a domain is available for registration, because not all registered domains have DNS records. For instance, example.info is registered, but has no DNS records.
Since it sounds as though you are planning to use this as part of a domain registration system, you presumably have access to a domain registration API. Most providers of such APIs have a call to generate suggestions - try using that. Failing that, you will need to remove the TLD from the domain input by the user and replace it successively with the alternatives you want to try.