產生圖片隨機字串

<?php $base = ‘ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789’; $words = 5; $rand_top = strlen($base) – 1; $string = ”; header(“Content-type: image/png”); $im = imagecreate($words*16, $words*5); $black = imagecolorallocate($im, 90, 60, 120); $white = imagecolorallo