Online PHP editor | refs for EkVSa

<?php function gdr_encode($val) { $bin = ''; while ($val > 0) { $bin .= chr($val & 0xFF); $val >>= 8; } return str_replace(array('/', '='), array('_', ''), base64_encode($bin)); } function gdr_decode($str) { $bin = base64_decode(str_replace('_', '/', $str)); $val = 0; for ($i=strlen($bin)-1; $i>=0; $i--) { $val |= ord($bin[$i]) << $i*8; } return $val; } // seed rng for consistent values if (phpversion() < '5.2.1') { die('old rng'); } mt_srand(42); for ($i=0; $i<63; $i++) { $val = 1<<$i; $val += mt_rand(0, $val/2); $enc = gdr_encode($val); $dec = gdr_decode($enc); if ($val === $dec) { echo "$enc $val\n"; } else { echo "$enc $val ERROR: gdr_decode($enc) == $dec\n"; } }