Some string masking functions using PHP

string_masking_functions.php

<?php

function maskString($str)
{
    $result = '';
    $parts = explode(' ', $str);

    foreach ($parts as $part) {
        if (!empty($part)) {
            if (strlen($part) == 1) {
                $result .= '*';
            } else {
                $result .= mb_substr($part, 0, 1);
                $result .= str_repeat('*', strlen($part) - 1);
                $result .= ' ';
            }
        }
    }

    if (empty($result)) {
        return $str;
    }

    if (strlen($result) > 1) {
        // remove the last space char
        $result = substr($result, 0, strlen($result) - 1);
    }


    return $result;
}

function maskEmailAddress($email)
{
    $parts = explode('@', $email);

    if (count($parts) <= 1) {
        return $email;
    }

    return maskString($parts[0]) . '@' . $parts[1];
}

?>