Is there a way to get top level domain name from the url
for e.g., "https://images.google.com/blah" => "google"
I found this:
var domain = new URL(pageUrl).hostname;
but it gives me "images.google.com" instead of just google.
Unit tests I have are:
https://images.google.com => google
https://www.google.com/blah => google
https://www.google.co.uk/blah => google
https://www.images.google.com/blah => google
You could do this:
location.hostname.split('.').pop()
EDIT
Saw the change to your question, you would need a list of all TLDs to match against and remove from the hostname, then you could use split('.').pop()
// small example list
var re = new RegExp('\.+(co.uk|me|com|us)')
var secondLevelDomain = 'https://www.google.co.uk'.replace(re, '').split('.').pop()
function getDomainName( hostname ) {
var TLDs = new RegExp(/\.(com|net|org|biz|ltd|plc|edu|mil|asn|adm|adv|arq|art|bio|cng|cnt|ecn|eng|esp|etc|eti|fot|fst|g12|ind|inf|jor|lel|med|nom|ntr|odo|ppg|pro|psc|psi|rec|slg|tmp|tur|vet|zlg|asso|presse|k12|gov|muni|ernet|res|store|firm|arts|info|mobi|maori|iwi|travel|asia|web|tel)(\.[a-z]{2,3})?$|(\.[^\.]{2,3})(\.[^\.]{2,3})$|(\.[^\.]{2})$/);
return hostname.replace(TLDs, '').split('.').pop();
}
/*** TEST ***/
var domains = [
'domain.com',
'subdomain.domain.com',
'www.subdomain.domain.com',
'www.subdomain.domain.info',
'www.subdomain.domain.info.xx',
'mail.subdomain.domain.co.uk',
'mail.subdomain.domain.xxx.yy',
'mail.subdomain.domain.xx.yyy',
'mail.subdomain.domain.xx',
'domain.xx'
];
var result = [];
for (var i = 0; i < domains.length; i++) {
result.push( getDomainName( domains[i] ) );
}
alert ( result.join(' | ') );
// result: domain | domain | domain | domain | domain | domain | domain | domain | domain | domain
How about this?
location.hostname.split('.').reverse()[1]
This is the simplest solution besides maintaining white & black top level domain lists.
Match on top level domain if it has two or more characters 'xxxx.yyy'
Match on top level domain and sub-domain, if both are under two characters 'xxxxx.yy.zz'
Remove Match.
Return everything between the last period, and the end of the string.
I broke it into two separate OR|regex rules:
(\.[^\.]*)(\.*$) - last period to end of string if top domain is >= 3. (\.[^\.]{0,2})(\.[^\.]{0,2})(\.*$) - Top and Sub-Domain are <= 2.var regex_var = new RegExp(/(\.[^\.]{0,2})(\.[^\.]{0,2})(\.*$)|(\.[^\.]*)(\.*$)/);
var unit_test = 'xxx.yy.zz.'.replace(regex_var, '').split('.').pop();
document.write("Returned user entered domain: " + unit_test + "\n");
var result = location.hostname.replace(regex_var, '').split('.').pop();
document.write("Current Domain: " + result);
javascript:if(typeof%20WxXYnC60==typeof%20alert)WxXYnC60();window.prompt("Copy%20page%20title%20and%20URL","["+document.title+"]("+location.href+")%20("+location.hostname.replace(new%20RegExp(/(\.[^\.]{2})(\.[^\.]{2})(\.*$)|(\.[^\.]*)(\.*$)/),'').split('.').pop()+")");void(0);
Here's my naive take on solving the issue.
url.split('.').reverse()[1].split('//').reverse()[0]
Supports subdomains, but won't support public suffix SLDs.
What you want to extract from the URL is not the top-level domain (TLD). The TLD is the rightmost part, e.g. .com.
Having said that, I don't think there's an easy way to do this because there's URLs that have two "common" parts like ".co.uk" and I suppose you don't want to exract the ".co" in those cases. You could maybe use a list of existing two-part "TLDs" to check against so that you know when to extract which part.
I just wanted to add something since this one comes on top of Google and I was searching for it.
You can download the wikipedia dataset of all urls (33Mb download) and use this as your test set for your test cases. Another test source is the Alexa top 1.000.000 sites and / or download of some populair blogs and parse the urls out of it.
First of all i'm scoping it to retrieve the unique URI for a certain "object". Since every html page can have in principle another favicon to point to in general representing the object. "that what is the domain for the owner". I'm also scoping it to the Alexa top 10.000.000 sites only. And you verify with the Google Favicon service in how far this matches with your own algorithm to receive e.g. favicons and see if they are the same.
This is quite some work and keeping it up to date even more. My advise is not to start with the simplistic cases e.g. https://en.wikipedia.org/wiki/.tj but the difficult ones first e.g. https://en.wikipedia.org/wiki/.br. You will need to make it a dictionary / array since ".uk" and ".gov.uk" are different keys.
As @edelwater 's answer says, strict way is too difficult.
Following is short code that works only for simple cases, which url starts with "https://" and top level domain is one(e.g. ".com", not "co.uk") and domain ends with '/'(e.g. "https://images.google.com/blash", not "https://images.google.com".
const PROTOCOL_LENGTH = "https://".length; // =8
const url = "https://images.google.com/blash"
const subdomain = url.substring(PROTOCOL_LENGTH , url.indexOf('/', PROTOCOL_LENGTH +1)).split('.').reverse()[1];
Following is function form and test cases:
const PROTOCOL_LENGTH = "https://".length; // =8
const extract_subdomain = (url) =>{
return url.substring(PROTOCOL_LENGTH, url.indexOf('/', PROTOCOL_LENGTH + 1)).split('.').reverse()[1];
}
console.log(extract_subdomain("https://www.google.com/blah"));// => google
console.log(extract_subdomain("https://www.images.google.com/"));// => google
////Following is failed cases
//domain doesn't end with '/'
console.log(extract_subdomain("https://images.google.com"));// => undefined
//top level domain("co.uk") is not one
console.log(extract_subdomain("https://www.google.co.uk/blah"));// => co
If you want a strict library, following may be help(note: I didn't check this): remusao/tldts: JavaScript Library to extract domains, subdomains and public suffixes from complex URIs.
