JS前夜
JS具有脚本、浏览器运行的特性，方便使用。简单的工具应该使用JS+HTML来制作。
<html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8" /><title>URL转换</title> </head><body><p>用于 <a href="http://goxiazai.cc/"> http://goxiazai.cc/</a> MAC下载无法获取迅雷url的转换</p>输入URL :</p><textarea id="urlText" type="text" name="url" rows="5" cols="100">http://goxiazai.cc/xiazai.html?cid=8C1A3F3F9D6BD0CCE606AC73E8B22231B1D4B1D1&f=thunder%3a%2f%2fQUFodHRwOi8vZ2d4eHh6enouY29tOjgwODkvW2dveGlhemFpLmNjXVsyMDEyw8C5%2btfu0MKwrMLqoaTO1smtuN%2b31sfgtLqwrsfps8mzpF1bsdq7qMnZxOpdWzcyMFC438flXVvW0NOiy6vX1l1bSU1EQiA4LjRdW9G4wNfPwtTYXS5ybXZiWlo%3d</textarea></p><button onclick="urlFunction()">Submit</button></p><p>结果:</p><textarea id="result" type="text" name="url" rows="5" cols="100"></textarea><script>function urlFunction(){ var result = "input url error"; var url = document.getElementById("urlText").value; var start = url.indexOf("thunder"); if (start > 0) { url = url.substr(start); result = decodeURIComponent(url); } document.getElementById("result").innerHTML = result;}</script></body></html>