String pad

str_pad.php

    /**
     * @param string $string
     * @param string $pad
     * @param int $expected_length
     * @return string
     */
    function str_pad($string, $pad, $expected_length)
    {
        $left = $expected_length - strlen($string);
        while ($left > 0) {
            $string = $pad.$string;
            $left --;
        }
        return $string;
    }