Check if URL entered is from a certain domain

Question

I have a field where a user can enter a URL. I need to check if that URL is from a certain domain, in this case google.com.

I've tried this, however, it doesn't work for all cases (which I list below):

if(strstr(parse_url($link, PHP_URL_HOST), 'google.com') { // continue }

• http://www.google.com/blah - works
• https://www.google.com/blah - works
• google.com/blah - doesn't work
• www.google.com/blah - doesn't work

Is there a way to do this without regex? If not, how would it be done?

Thanks.

Answer 1

parse_url requires a valid URL and google.com/blah isn't valid (as of PHP 5.3.3) -- so it won't work. As a work around, you can append the http if doesn't exist already, and then check the domain.

Use the following function:

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

    $domain = implode('.', array_slice(explode('.', parse_url($url, PHP_URL_HOST)), -2));
    if ($domain == 'google.com') {
        return True;
    } else {
        return False;
    }

}

Test cases:

var_dump(checkRootDomain('http://www.google.com/blah'));
var_dump(checkRootDomain('https://www.google.com/blah '));
var_dump(checkRootDomain('google.com/blah'));
var_dump(checkRootDomain('www.google.com/blah '));

Result:

bool(true) 
bool(true) 
bool(true) 
bool(true)

It is a modified version of my own answer here.

Hope this helps!