Convert subdomain to domain name (sub TLD vs TLD)

Question

I have written a function that "extract" the domain from hostname. e.g.

www.domain.com -> domain.com
domain.net -> domain.net
www.domain.co.uk -> domain.co.uk
www.subdomain.domain.tx.us -> domain.tx.us

and so on.

However I was unable to find list of all subTDL's.

Function also return wrong result for domains such nominet.uk

Any suggestions where I can find all of them?

Or any other way to do same function, but with using let say DNS?

score 2 · Answer 1 · answered Jul 01 '12 at 11:14

2

It's impossible to this using the DNS (or any other algorithm for that matter) as there's no formal definition of what is a "subdomain".

The only practical solution at the moment is the "public suffix" list available via http://publicsuffix.org/.

This list contains those domains known to the administrators where different subdomains are issued to different third parties.

Its primary use is to help enforce cross-domain security policies - for example a server for "foo.co.uk" mustn't be able to set a domain cookie on "co.uk" which is then served to any other subdomain.

answered Jul 01 '12 at 11:14

Alnitak

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Yep, this is same file I'm referring to. – Nick Jul 02 '12 at 15:30
@Nick yes, I know. I was adding context, and a link to the parent site which explains it, not just the raw file. – Alnitak Jul 02 '12 at 15:47

score 0 · Accepted Answer · answered Jun 29 '12 at 11:07

0

There is publicly available file describing all sub TLD's located at:

http://mxr.mozilla.org/mozilla-central/source/netwerk/dns/effective_tld_names.dat?raw=1

answered Jun 29 '12 at 11:07

Nick

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Convert subdomain to domain name (sub TLD vs TLD)

2 Answers2