Question

我计划制作一个可以将文件编码为ASCII字符并解码为可读文本的类。基本上，我的编码思路是将所有非空格字符编码为ASCII，然后将空格替换为随机的非数字字符。

Example: "Hello World!" to "72101108108111^8711111410810033"

以这种方式，如果我有一个包含多个段落的整个文件并对其进行编码，那么将字符转换为ASCII并不是很明显。到目前为止，这是我的代码：

$text = str_split("Hello World!");
$content = "";
$random = str_split("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!@#$%^&*-+?/_=");
foreach($text as $t){
    if ($t == " "){
        $count = rand(1,66);
        $content .= $random[$count-1];
    }
    else
        $content .= ord($t);
}
echo $content."<br>";
$decode = str_split($content);
$script = "";
$tostring = "";
foreach($decode as $d){
    if (is_numeric($d)){
        $tostring .= $d;
    }else{
        $script .= chr($tostring);
        $tostring = "";
    }
}

echo $script;

我正在努力找出我的代码存在的问题。这是它的结果：

ASCII: 72101108108111-8711111410810033
TEXT: O

请赐教！

Answer 1

两个问题：您试图将多个数字传递给旨在返回单个字符的chr()，并且您无法知道数字将要持续多久。使用上面的示例：是72、101、108、108还是72、10、10、81、08？因此，使用sprintf()将数字固定为3位数字，然后您将知道何时将数据传递到chr()并继续进行解码。

$text = str_split("Hello World!");
$content = "";
$random = str_split("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!@#$%^&*-+?/_=");
foreach($text as $t){
    if ($t === " "){
        $count = rand(1, 66);
        $content .= $random[$count - 1];
    } else {
        // this will always be three digits now
        $content .= sprintf("%03d", ord($t));
    }
}
echo $content."<br>";
$decode = str_split($content);
$script = "";
$tostring = "";
foreach($decode as $d){
    if (is_numeric($d)){
        $tostring .= $d;
        if (strlen($tostring) === 3) {
            // you've got 3 numbers so you can decode and reset
            $script .= chr($tostring);
            $tostring = "";
        }
    } else {
        // also you weren't putting your spaces back in
        $script .= " ";
    }
}

echo $script;

PHP将文本编码和解码为ASCII字符

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