パスワードもどきを簡単に生成

mkpassword.php

<?php
function makePass($length = 8) {
	$base = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	$str = "";
	while($length--) {
		$str .= $base[mt_rand(0, strlen($base) - 1)];
	}
	return $str;
}
var_dump(makePass(20));

$num = mt_rand();
var_dump($num);
var_dump(base_convert($num, 10, 36));
var_dump(str_replace("=", "", base64_encode($num)));


$bytes = openssl_random_pseudo_bytes(10);
var_dump(str_replace("=", "", base64_encode($bytes)));
var_dump(bin2hex($bytes));

参考サイト
http://qiita.com/suin/items/c958bcca90262467f2c0