HTML 向后包含脚本

Question

I know that one can include JS in their HTML files with a <script src=""></script> include, but can you specify it to load in the script src backwards (reading line by line bottom to top instead of top to bottom)?我知道可以在他们的 HTML 文件中包含 JS，其中包含一个<script src=""></script> ，但是你能指定它向后加载脚本src （从下到上而不是从上到下逐行读取）底部）？ I would not like to include the script src with any inline JS or anything like that: it needs to be simply included in (but from bottom to top instead of top to bottom).我不想将脚本src包含在任何内联 JS 或类似的东西中：它需要简单地包含在（但从下到上而不是从上到下）。 Further, I understand I could just flip the script around so that loading it top to bottom isn't an issue, but I would like to know if there is any way I could simply load from bottom to top.此外，我知道我可以翻转脚本，以便从上到下加载它不是问题，但我想知道是否有任何方法可以简单地从下到上加载。

For example, here's a test.js file:例如，这是一个test.js文件：

alert("line 1!");
alert("line 2!");
alert("line 3!");

And if I include it in a test.html file, I could do this in the <head></head> or <body></body> :如果我将它包含在test.html文件中，我可以在<head></head>或<body></body>中执行此操作：

<script src="test.js"></script> <!-- Assuming They are in the same directory -->

Now when this test.js gets included, it is (as far as I am aware) going to read test.js from top to bottom, so alert("line 1!") will run before alert("line 3!") .现在，当包含此test.js时，它（据我所知）将从上到下读取test.js ，因此alert("line 1!")将在alert("line 3!")之前运行. And, if let's say line 1 in test.js is invalid, then the whole script stops getting included.而且，如果假设test.js中的第 1 行无效，那么整个脚本将停止包含在内。 I am wondering if I can do a <script src="test.js"></script> include where line 3 (the last line) gets read first (so alert("line 3!") ) and the first line gets read last ( alert("line 1!") ).我想知道我是否可以做一个<script src="test.js"></script> include 其中第 3 行（最后一行）首先被读取（所以alert("line 3!") ）并且第一行被读取最后阅读（ alert("line 1!") ）。 I am doing a cyber security challenge and I know that the top of the file I am trying to include is not valid JS, but the bottom is, so theoretically if I can include it from bottom to top I could get my JS to execute before it throws an error.我正在做一个网络安全挑战，我知道我试图包含的文件顶部不是有效的 JS，但底部是，所以理论上如果我可以从下到上包含它，我可以让我的 JS 在执行之前它抛出一个错误。

Answer 1

You can create a function that executes the script contents backward by sending an AJAX request to the target URL, splitting the response by a newline, reversing the resulting array, join into a string then use eval .您可以创建一个 function，它通过向目标 URL 发送 AJAX 请求向后执行脚本内容，用换行符拆分响应，反转结果数组，加入一个字符串，然后使用eval 。

Something like this:是这样的：

function loadScriptBackwards(url) {
  var xhttp;
  xhttp = new XMLHttpRequest();
  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      eval(this.responseText.split("\n").reverse().join('\n'))
    }
  };
  xhttp.open("GET", url, true);
  xhttp.send();
}

HTML 向后包含脚本

问题描述

1 个解决方案

解决方案1
1 已采纳 2021-10-06 23:09:28

HTML 向后包含脚本

问题描述

1 个解决方案

解决方案1 1 已采纳 2021-10-06 23:09:28

解决方案1
1 已采纳 2021-10-06 23:09:28