[PHP]利用openssl_random_pseudo_bytes和base64_encode函数来生成随机字符串_PHP教程

<code class="language-php hljs ">public static function getRandomString($length = 42)
    {
        /*
         * Use OpenSSL (if available)
         */
        if (function_exists(&#39;openssl_random_pseudo_bytes&#39;)) {
            $bytes = openssl_random_pseudo_bytes($length * 2);

            if ($bytes === false)
                throw new RuntimeException(&#39;Unable to generate a random string&#39;);

            return substr(str_replace([&#39;/&#39;, &#39;+&#39;, &#39;=&#39;], &#39;&#39;, base64_encode($bytes)), 0, $length);
        }

        $pool = &#39;0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ&#39;;

        return substr(str_shuffle(str_repeat($pool, 5)), 0, $length);
    }</code>

<code class="language-php hljs ">substr(str_shuffle(str_repeat($pool, 5)), 0, $length);</code>