How do you strip out the domain name from a URL in php?

Question

Im looking for a method (or function) to strip out the domain.ext part of any URL thats fed into the function. The domain extension can be anything (.com, .co.uk, .nl, .what

Answer 1

You can also write a regular expression to get exactly what you want.

Here is my attempt at it:

$pattern = '/\w+\..{2,3}(?:\..{2,3})?(?:$|(?=\/))/i';
$url = 'http://www.example.com/foo/bar?hat=bowler&accessory=cane';
if (preg_match($pattern, $url, $matches) === 1) {
    echo $matches[0];
}

The output is:

example.com

This pattern also takes into consideration domains such as 'example.com.au'.

Note: I have not consulted the relevant RFC.

Answer 2

This function should work:

function Delete_Domain_From_Url($Url = false)
{
    if($Url)
    {
        $Url_Parts = parse_url($Url);
        $Url = isset($Url_Parts['path']) ? $Url_Parts['path'] : '';
        $Url .= isset($Url_Parts['query']) ? "?".$Url_Parts['query'] : '';
    }

    return $Url;
}

To use it:

$Url = "https://stackoverflow.com/questions/176284/how-do-you-strip-out-the-domain-name-from-a-url-in-php";
echo Delete_Domain_From_Url($Url);

# Output: 
#/questions/176284/how-do-you-strip-out-the-domain-name-from-a-url-in-php

Answer 3

Here are a couple simple functions to get the root domain (example.com) from a normal or long domain (test.sub.domain.com) or url (http://www.example.com).

/**
 * Get root domain from full domain
 * @param string $domain
 */
public function getRootDomain($domain)
{
    $domain = explode('.', $domain);

    $tld = array_pop($domain);
    $name = array_pop($domain);

    $domain = "$name.$tld";

    return $domain;
}

/**
 * Get domain name from url
 * @param string $url
 */
public function getDomainFromUrl($url)
{
    $domain = parse_url($url, PHP_URL_HOST);
    $domain = $this->getRootDomain($domain);

    return $domain;
}

Answer 4

There is only one correct way to extract domain parts, it's use Public Suffix List (database of TLDs). I recomend TLDExtract package, here is sample code:

$extract = new LayerShifter\TLDExtract\Extract();

$result = $extract->parse('www.domain.com/path/script.php?=whatever');
$result->getSubdomain(); // will return (string) 'www'
$result->getHostname(); // will return (string) 'domain'
$result->getSuffix(); // will return (string) 'com'

Answer 5

You can use parse_url() to do this:

$url = 'http://www.example.com';
$domain = parse_url($url, PHP_URL_HOST);
$domain = str_replace('www.','',$domain);

In this example, $domain should contain example.com, irrespective of it having www or not. It also works for a domain such as .co.uk

Answer 6

I spent some time thinking about whether it makes sense to use a regular expression for this, but in the end I think not.

firstresponder's regexp came close to convincing me it was the best way, but it didn't work on anything missing a trailing slash (so http://example.com, for instance). I fixed that with the following: '/\w+\..{2,3}(?:\..{2,3})?(?=[\/\W])/i', but then I realized that matches twice for urls like 'http://example.com/index.htm'. Oops. That wouldn't be so bad (just use the first one), but it also matches twice on something like this: 'http://abc.ed.fg.hij.kl.mn/', and the first match isn't the right one. :(

A co-worker suggested just getting the host (via parse_url()), and then just taking the last two or three array bits (split() on '.') The two or three would be based on a list of domains, like 'co.uk', etc. Making up that list becomes the hard part.