<?php
function random($len) {
$token = "";
//Aquí tus posibles caracteres
for ($i = 0; $i < $len; $i++) {
}
return $token;
}
echo random(30);
PD9waHAKZnVuY3Rpb24gcmFuZG9tKCRsZW4pIHsKICAgICR0b2tlbiA9ICIiOwogICAgLy9BcXXDrSB0dXMgcG9zaWJsZXMgY2FyYWN0ZXJlcwogICAgJGtleXMgPSBhcnJheV9tZXJnZShyYW5nZSgwLCA5KSwgcmFuZ2UoJ2EnLCAneicpLCByYW5nZSgnQScsICdaJykpOwogICAgZm9yICgkaSA9IDA7ICRpIDwgJGxlbjsgJGkrKykgewogICAgCSR0b2tlbiAuPSAka2V5c1thcnJheV9yYW5kKCRrZXlzKV07CiAgICB9CiAgICByZXR1cm4gJHRva2VuOwp9CmVjaG8gcmFuZG9tKDMwKTs=