Function to cast the shorthand memory notation value to bytes

return_bytes.php

/**
 * Converts shorthand memory notation value to bytes
 * From http://php.net/manual/en/function.ini-get.php
 *
 * @param string $val memory size shorthand notation string
 * @return int|string
 */
function return_bytes($val)
{
    $val = trim($val);
    $last = strtolower($val[strlen($val) - 1]);
    $val = substr($val, 0, -1);

    switch ($last) {
        // The 'G' modifier is available since PHP 5.1.0
        case 'g':
            $val *= 1024;
        case 'm':
            $val *= 1024;
        case 'k':
            $val *= 1024;
    }

    return $val;
}