This .NET Standard 2 library and Command line tool extracts the root domain, subdomain name, and top level domain from a URL, using the the Public Suffix List.
This is based on the Go TldExtract and the Python TldExtract libraries from:
This library is useful as it uses the public database to sort out what is the domain, the TLD and the root domain, without using assumptions as to what the contents are.
Some examples:
| Host name | Subdomain | Root domain | Top-level Domain |
|---|---|---|---|
| www.google.co.uk | www | co.uk | |
| forums.news.cnn.com | forums.news | cnn | com |
| google.notavalidsuffix | notavalidsuffix | ||
| media.forums.theregister.co.uk | media.forums | theregister | co.uk |
| www.cgs.act.edu.au | www | cgs | act.edu.au |
| joe.blogspot.co.uk | joe | blogspot.co.uk | |
| wiki.info | wiki | info |
Add the TldExtract library NuGet package to your solution, and then create an instance of the
NStack.TldExtract class. You can either provide a path to the cache file where you want the
public suffix list to be downloaded or nothing and the library will choose the proper cache
location for you.
Then invoke the Extract method that will return a tuple of values with the subdomain, the root domain and the TLD domain.
var extractor = new NStack.TldExtract ();
(var sub, var root, var tld) = extractor.Extract ("www.microsoft.com");