从字符串中删除随机生成的字符，以明文形式显示单词 - Remove random generated characters from a string to display the word in clear text

Remove random generated characters from a string to display the word in clear text

我有这个函数将一些随机字符放入字符串中：

function random($string) {
    $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    $shuffle_start = substr(str_shuffle($chars), 0, 6);
    $shuffle_end = substr(str_shuffle($chars), 0, 6);
    $letters = str_split($string);
    $str = '';
    $count = count($letters);
    foreach($letters AS $l) {
        $count--;
        $str .= $l;
        if($count) {
            $str .= substr(str_shuffle($chars), 0, 5);
        }
    }
    return $shuffle_start . $str . $shuffle_end;
}

此函数从字符串"hello"中打印以下内容：aApi3VhKJrDjeAbCkalprX7ll7N0Qjo3qymiw 。现在，我想从字符串中删除随机字符，以便清楚地看到单词"hello"。

我该怎么做？

向后移动。从开头和结尾去除 6 个字符，然后每 6 个字符获取一次

function unrandom($str){
    $base = substr($str, 6, strlen($str)-12);
    $ret = '';
    for($i=0;$i < strlen($base); $i+=6) {
        $ret .= substr($base, $i,1);
    }
    return $ret;
}