console 命令行工具 X clear

console

function doSave(value, type, name) {
    var blob;
    if (typeof window.Blob == "function") {
        blob = new Blob([value], { type: type });
    } else {
        var BlobBuilder = window.BlobBuilder || window.MozBlobBuilder || window.WebKitBlobBuilder || window.MSBlobBuilder;
        var bb = new BlobBuilder();
        bb.append(value);
        blob = bb.getBlob(type);
    }
    var URL = window.URL || window.webkitURL;
    var bloburl = URL.createObjectURL(blob);
    var anchor = document.createElement("a");
    if ('download' in anchor) {
        anchor.style.visibility = "hidden";
        anchor.href = bloburl;
        anchor.download = name;
        document.body.appendChild(anchor);
        var evt = document.createEvent("MouseEvents");
        evt.initEvent("click", true, true);
        anchor.dispatchEvent(evt);
        document.body.removeChild(anchor);
    } else if (navigator.msSaveBlob) {
        navigator.msSaveBlob(blob, name);
    } else {
        location.href = bloburl;
    }
}

var savebtn = document.getElementById('save')
savebtn.addEventListener('click', function () {
    var filename = document.getElementById('filename').value
    var filecontent = document.getElementById('filecontent').value
    doSave(filecontent, "text/latex", filename + ".txt")
})

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>创建文件与下载</title>
</head>
<body>
    <input id="filename" type="text" placeholder="文件名">
    <br><br>
    <textarea id="filecontent" cols="30" rows="10" placeholder="输入内容"></textarea>
    <br><br>
    <input id="save" type="button" value="Save"/>
</body>
<script src="js/app.js"></script>
</html>