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

You could always do something like this:

$good_domains = array('school.edu'); //in the future, just add to this array for more schools

$email = "user@school.edu"; //your user's email

$matches = array();
preg_match("/^(.+)@([^\(\);:,<>]+\.[a-zA-Z]+)/", $email, &$matches); //validates the email and gathers information about it simultaneously
//should return ['user@mail.com', 'user', 'mail.com']
$domain = $matches[3];

if(in_array($domain, $goood_domains))
{
    //success! your user is from school.edu!
}
else
{
    //oh no! an imposter!
}

Answer 2

If you are using Laravel:

Str::endsWith($email, '@foo.bar.edu'); // bool

Answer 3

I'd just do this:

 $acceptedDomains = array('site1.edu', 'site2.edu');

 if(in_array(substr($email, strrpos($email, '@') + 1), $acceptedDomains))
 {
    // Email is from a domain in $acceptedDomains
 }

The 'whatever.edu' portion will always be after the @. So, all you need to do is:

1. Find the last occurrence of @ in the string. (In a normal email, there will only be one, but that doesn't matter here.)
2. Get the portion of the email after the @. This will be the domain name.
3. Use in_array() to compare the domain name against a list of accepted domains in $acceptedDomains.

Note that if you want to also accept emails from email@any.subdomain.site1.edu, you'd have to do just a little more, but that may or may not be applicable here. I'm also assuming you've validated that the email addresses are well formed before doing this.

Answer 4

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
    }
}

Answer 5

Simple and Single line:

     list($name, $domain) = explode('@', $email);

Answer 6

You can use regex:

if(preg_match('/^\w+@school\.edu$/i', $source_string) > 0)
    //valid

Now proceed to tear me apart in the comments because there's some crazy email address feature I didn't account for :)