Re: Parse domain from URL

On 06/06/07, Brad Fuller <bfuller@cpacampaigns.com> wrote:

Daniel Brown wrote: On 6/6/07, Brad Fuller <bfuller@cpacampaigns.com> wrote:

I need to strip out a domain name from a URL, and ignore subdomains (like www) I can use parse_url to get the hostname. And my first thought was to take the last 2 segments of the hostname to get the domain.

So if the

URL is http://www.example.com/ Then the domain is "example.com." If the URL is http://example.org/ then the domain is "example.org." This seemed to work perfectly until I come across a URL like http://www.example.co.uk/ My script thinks the domain is "co.uk." So I added a bit of code to account for this, basically if the 2nd to last segment of the hostname is "co" then take the last 3 segments. Then I stumbled across a URL like http://www.example.com.au/ So it occurred to me that this is not the best solution, unless I have a definitive list of all exceptions to go off of. Does anyone have any suggestions? Any advice is much appreciated.

    Well, it's not very clean, but if you just need to remove

the subdomain/CNAME from the domain.... <? $hostname = parse_url($_SERVER['SERVER_NAME']); $domsplit = explode('.',$hostname['path']); for($i=1;$i<count($domsplit);$i++) {

        $i == (count($domsplit) - 1) ? $domain .= $domsplit[$i] :

$domain .= $domsplit[$i]."."; } echo $domain;

    There's probably a much better way to do it, but in the

interest of a quick response, that's one way. Yes, that's basically what my code already does. The problem is that what if the url is "http://yahoo.co.uk/" (note the lack of a subdomain) Your script thinks that the domain is "co.uk". Just like my existing code does. So we can't count on taking the last 2 segments. And we can't count on ignoring the first segment. (The subdomain could be anything, not just www)

In that case you can't do it just by parsing alone, you need to use DNS. <?php function get_domain ($hostname) { dns_get_record($hostname, DNS_A, $authns, $addt); return $authns[0]['host']; } print get_domain("www.google.com") . "\n"; print get_domain("google.com") . "\n"; print get_domain("www.google.co.uk") . "\n"; print get_domain("google.co.uk") . "\n"; print get_domain("google.co.uk") . "\n"; print get_domain("google.com.au") . "\n"; print get_domain("www.google.com.au") . "\n"; /* result google.com google.com google.co.uk google.co.uk google.co.uk google.com.au google.com.au */ ?>