CODEWITHSUNDEEP
phpregexsubdomain
hakki
hakki

Reputation: 6501

Get domain with its subdomain from url

I'm using this function to get domain and subdomain from a string. But If string is already my expected format, it returns null

function getDomainFromUrl($url) {
    $host = parse_url($url, PHP_URL_HOST);
    return preg_replace('/^www\./', '', $host);
}

$url = "http://abc.example.com/" -> abc.example.com | OK

$url = "http://www.example.com/" -> example.com | OK

$url = "abc.example.com" -> FAILS!

Upvotes: 5

Views: 1829

Answers (4)

Schlaus
Schlaus

Reputation: 19182

Here's a pure regex solution:

function getDomainFromUrl($url) {
    if (preg_match('/^(?:https?:\/\/)?(?:(?:[^@]*@)|(?:[^:]*:[^@]*@))?(?:www\.)?([^\/:]+)/', $url, $parts)) {
        return $parts[1];
    }
    return false; // or maybe '', depending on what you need
}

getDomainFromUrl("http://abc.example.com/"); // abc.example.com

getDomainFromUrl("http://www.example.com/"); // example.com

getDomainFromUrl("abc.example.com");         // abc.example.com

getDomainFromUrl("[email protected]"); // abc.example.com

getDomainFromUrl("https://username:[email protected]"); // abc.example.com

getDomainFromUrl("https://username:[email protected]:123"); // abc.example.com

You can try it here: http://sandbox.onlinephpfunctions.com/code/3f0343bbb68b190bffff5d568470681c00b0c45c

In case you want to know more about the regex:

^                 matching must start from the beginning on the string
(?:https?:\/\/)?  an optional, non-capturing group that matches http:// and https://

(?:(?:[^@]*@)|(?:[^:]*:[^@]*@))?
                  an optional, non-capturing group that matches either *@ or *:*@ where * is any character
(?:www\.)?        an optional, non-capturing group that matches www.
([^\/:]+)          a capturing group that matches anything up until a '/', a ':', or the end of the string

Upvotes: 3

Danijel
Danijel

Reputation: 12689

parse_url() function doesn't work with relative URLs. You can test if the sheme is present, and if not add the default one:

if ( !preg_match( '/^([^\:]+)\:\/\//', $url ) ) $url = 'http://' . $url;

Upvotes: 0

maxisme
maxisme

Reputation: 4245

That is because abc.example.com is not a PHP_URL_HOST so you need to first check that it is one first. So you should do something simple like this, where if the url is doesn't have a protocol -> add it:

function addhttp($url) {
    if (!preg_match("~^(?:f|ht)tps?://~i", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

function getDomainFromUrl($url) {
    $host = parse_url($url, PHP_URL_HOST);
    if($host){
        return preg_replace('/^www\./', '', $host);
    }else{
        //not a url with protocol
        $url = addhttp($url); //add protocol
        return getDomainFromUrl($url); //run function again.
    }
}

Upvotes: 3

chris85
chris85

Reputation: 23892

The issue is that parse_url is returning false. Check to make sure you get a response before trying to use it otherwise $host is empty.

<?php
function getDomainFromUrl($url) {
    $host = (parse_url($url, PHP_URL_HOST) != '') ? parse_url($url, PHP_URL_HOST) : $url;
    return preg_replace('/^www\./', '', $host);
}
echo getDomainFromUrl("http://abc.example.com/") . "\n";
echo getDomainFromUrl("http://www.example.com/") . "\n";
echo getDomainFromUrl("abc.example.com");

Output:

abc.example.com
example.com
abc.example.com

Upvotes: 1

Related Questions