get host name from domain REGEX javascript - Stack Overflow

What i try to do is when i have:

www.gmail,

www.gmail/,

,

,

,

,

www.gmail/example

just get gmail, by far from searching into relative questions i have pattern to match these things which is:

var pat = /^(https?:\/\/)?(?:www\.)?([^\/]+)/;

but it also returns true when i put also a word eg. gmail (without ). How can i improve this to match things that are of the form abcd.efgs ? I mean specify that the string should contain characters and at least one dot after the http,https,www. ?

Thanks in advance!

What i try to do is when i have:

www.gmail.,

www.gmail./,

http://www.gmail.,

https://www.gmail.,

http://gmail.,

https://gmail.,

www.gmail./example

just get gmail., by far from searching into relative questions i have pattern to match these things which is:

var pat = /^(https?:\/\/)?(?:www\.)?([^\/]+)/;

but it also returns true when i put also a word eg. gmail (without .). How can i improve this to match things that are of the form abcd.efgs. ? I mean specify that the string should contain characters and at least one dot after the http,https,www. ?

Thanks in advance!

• javascript
• regex
• dns
• pattern-matching

Share Improve this question Follow asked Oct 31, 2014 at 9:30 sstaurosssstauross 2,67822 gold badges3232 silver badges5151 bronze badges

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3 Answers 3

Sorted by: Reset to default 5

If my understanding is right, you want to match only the domain names of a URL.

You can do this with this pattern

(?:\w+\.)+\w+

I have copied your JavaScript Fiddle and made changes to demonstrate this using html text and textarea boxes. The textbox demo, extracts the domain name from a user entered URL. The textarea box demo lists all the domains in the entered multiline text.

http://jsfiddle/q6z3xb6d/

[update]

Just read your question again. Looks like you want to exclude matches for domains beginning with www. You can use this pattern for that:

(?!(w+)\.)\w*(?:\w+\.)+\w+

JS fiddle demo - Updated version:

http://jsfiddle/q6z3xb6d/2/

^(?:https?:\/\/)?(?:www\.)?((?:(?!www\.|\.).)+\.[a-zA-Z0-9.]+)

Try this.See demo.

http://regex101./r/yG7zB9/7

Given an input field like:

<input type='text' id='domain'/>

i ended up with this solution in which i first validate it as a url and then get the string without 'http://', 'https://' , 'www.'

$(document).ready(function(){

function ValidUrl(str) {
  var pattern = new RegExp('^(https?:\\/\\/)?'+ // protocol
  '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|'+ // domain name
  '((\\d{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) address
  '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*'+ // port and path
  '(\\?[;&a-z\\d%_.~+=-]*)?'+ // query string
  '(\\#[-a-z\\d_]*)?$','i'); // fragment locator
  if(!pattern.test(str)) {
    return false;
  } else {
    return true;
  }
}

$('#domain').change(function(){
    var str = $.trim($(this).val());
    if(ValidUrl(str)){
       var pat = /^(https?:\/\/)?(?:www\.)?([^\/]+)/;
       var match = str.match(pat);
        console.log(match);
         //$(this).val(str);
    }
    else{
        $(this).val('Validation failed');
    }
});
});

See also this jsfiddle:http://jsfiddle/6mrbbq9x/5/