Parsing domain from a URL

Question

I need to build a function which parses the domain from a URL.

So, with

http://google.com/dhasjkdas/sadsdds/sdda/sdads.html

or

Answer 1

Here is the code i made that 100% finds only the domain name, since it takes mozilla sub tlds to account. Only thing you have to check is how you make cache of that file, so you dont query mozilla every time.

For some strange reason, domains like co.uk are not in the list, so you have to make some hacking and add them manually. Its not cleanest solution but i hope it helps someone.

//=====================================================
static function domain($url)
{
    $slds = "";
    $url = strtolower($url);

            $address = 'http://mxr.mozilla.org/mozilla-central/source/netwerk/dns/effective_tld_names.dat?raw=1';
    if(!$subtlds = @kohana::cache('subtlds', null, 60)) 
    {
        $content = file($address);
        foreach($content as $num => $line)
        {
            $line = trim($line);
            if($line == '') continue;
            if(@substr($line[0], 0, 2) == '/') continue;
            $line = @preg_replace("/[^a-zA-Z0-9\.]/", '', $line);
            if($line == '') continue;  //$line = '.'.$line;
            if(@$line[0] == '.') $line = substr($line, 1);
            if(!strstr($line, '.')) continue;
            $subtlds[] = $line;
            //echo "{$num}: '{$line}'"; echo "
";
        }
        $subtlds = array_merge(Array(
            'co.uk', 'me.uk', 'net.uk', 'org.uk', 'sch.uk', 'ac.uk', 
            'gov.uk', 'nhs.uk', 'police.uk', 'mod.uk', 'asn.au', 'com.au',
            'net.au', 'id.au', 'org.au', 'edu.au', 'gov.au', 'csiro.au',
            ),$subtlds);

        $subtlds = array_unique($subtlds);
        //echo var_dump($subtlds);
        @kohana::cache('subtlds', $subtlds);
    }


    preg_match('/^(http:[\/]{2,})?([^\/]+)/i', $url, $matches);
    //preg_match("/^(http:\/\/|https:\/\/|)[a-zA-Z-]([^\/]+)/i", $url, $matches);
    $host = @$matches[2];
    //echo var_dump($matches);

    preg_match("/[^\.\/]+\.[^\.\/]+$/", $host, $matches);
    foreach($subtlds as $sub) 
    {
        if (preg_match("/{$sub}$/", $host, $xyz))
        preg_match("/[^\.\/]+\.[^\.\/]+\.[^\.\/]+$/", $host, $matches);
    }

    return @$matches[0];
}