Domain Name Checker

[eluser]RedIgniter[/eluser]
Hello everyone,

What is the best way to check if a domain name is available using PHP/CodeIgniter. Also what is the best structure for codeigniter (folder-wise). I've seen this thread but I cannot find it now. I've created something that checks domain name in PHP but it gives some errors. http://kayfer.com/myworks/domain_name_checker.

Thanks ahead,
- RedIgniter.

[eluser]smilie[/eluser]
What do you exactly mean with domain checker? Whois query?
I am using PHP exec() function to perform shell check (whois $domain) and parse the response. This will _not_ work on most shared hosting websites, but it is fastest way to perform whois check. Also, do bare in mind that some registries have limitations in number of whois queries (can be dealt with 'white listing' per whois server).
Whois through any API I have workd so far resulted in 'delay' of more then 400% percent (compared to shell).

In regard to folder-wise;
1 controller to receive user data, then:
- 1 helper which checks if user input is a valid TLD;
- 1 library to execute shell whois and in same library to parse return data and check for result.

Cheers,
Smilie