Question

I thought I had this figured out, but I’m running into an issue. I’m creating a URL blacklist in my application. I need to block all subdomains, directories, etc from an array of domains. Below is the array I have:

$blacklist = array(
'/\.google\./',
'/\.microsoft\./',
);   

Here is where I’m checking:

    $host = parse_url($url, PHP_URL_HOST);
    $blackList = $GLOBALS['blacklist'];
    foreach($blackList as $stop) {
        if (preg_match($host === $stop)) {
            die('blacklisted');
            }
        }

When I run this, it doesn’t die as intended.

Answer 1

Your foreach loop should be like this:

foreach($blacklist as $stop) {
        if (preg_match($stop, $host)) {
            die("blacklisted\n");
        }
}

You had 2 problems:

1. array variable was named as blacklist but you were using blackList in foreach loop.
2. preg_match was being used incorrectly, it needs at least 2 arguments like in my answer.