Check if URL is from a certain website

Question

Problem

The user can submit a form where he can submit a link to sitea.com. Now what I want to do is check if the user actually submitted an URL coming fr

Answer 1

I think it's best parse_url() here. Regex may work, but it's best to avoid using regex when a built-in function is available.

I'd do something like:

$url = '...';
$domain = implode('.', array_slice(explode('.', parse_url($url, PHP_URL_HOST)), -2));

if ($domain == 'sitea.com') {
    # code...
}

As a function:

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

}

Test cases:

var_dump(getDomain('http://sitea.com/'));
var_dump(getDomain('http://sitea.com/directory'));
var_dump(getDomain('http://subdomain.sitea.com/'));
var_dump(getDomain('http://sub.subdomain.sitea.com/#test'));

var_dump(getDomain('http://subdomain.notsitea.com/#dsdf'));
var_dump(getDomain('http://sitea.somesite.com'));
var_dump(getDomain('http://example.com/sitea.com'));
var_dump(getDomain('http://sitea.example.com/test.php?haha=sitea.com'));

Output:

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

bool(false)
bool(false)
bool(false)
bool(false)

Demo!