How to get a substring from string through PHP?

list($username, $domain) = explode('@', '[email protected]')

Use strstr function.

An example from the PHP reference -

<?php
    $email  = '[email protected]';
    $domain = strstr($email, '@');
    echo $domain; // prints @example.com

    $user = strstr($email, '@', true); // As of PHP 5.3.0
    echo $user; // prints name
?>

Try this:

$username = substr($username, 0, strpos($username, '@'));