PHP Check domain of email being registered is a 'school.edu' address

Question

I need to write a function for a project i\'m working on for fun, where we\'re making a site only accessible to students, staff, and alumni at an institution.

Let\'s

Answer 1

There's a few ways to accomplish this, here's one:

// Make sure we have input
// Remove extra white space if we do
$email = isset($_POST['email']) ? trim($_POST['email']) : null;

// List of allowed domains
$allowed = [
    'school.edu',
    'school2.edu',
    'school3.edu'
];

// Make sure the address is valid
if (filter_var($email, FILTER_VALIDATE_EMAIL))
{
    // Separate string by @ characters (there should be only one)
    $parts = explode('@', $email);

    // Remove and return the last part, which should be the domain
    $domain = array_pop($parts);

    // Check if the domain is in our list
    if ( ! in_array($domain, $allowed))
    {
        // Not allowed
    }
}