windows 上的 Node.Js - 如何清除控制台

Question

Being totally new into node.js environment and philosophy i would like answers to few questions. I had downloaded the node.js for windows installer and also node package manager.Windows Cmd prompt is being currently used for running nodejs apps.

1. cls clears the command window or errors in command prompt. Is there a equivalent for node.js? console.clear does not exist;( or does it in some other form?

2. I created a server through this code below

   var http = require("http"); http.createServer(function (request, response) { response.writeHead(200, { "Content-Type": "text/html" }); response.write("Hello World"); console.log("welcome world")response.end(); }).listen(9000, "127.0.0.1");

i changed the code to below and refreshed the browser to find that content type does not change, how do i get to see the changes?

var http = require("http");
http.createServer(function(request, response) {
  response.writeHead(200, {"Content-Type": "text/plain"});
  response.write("Hello World");
  console.log("welcome world")
  response.end();
}).listen(9000,"127.0.0.1");

Answer 1

console.log('\033[2J');

This works on linux. Not sure about windows.

You can "trick" the user using something like this:

var lines = process.stdout.getWindowSize()[1];
for(var i = 0; i < lines; i++) {
    console.log('\r\n');
}

Answer 2

process.stdout.write('\033c');

This also works on windows. Win7 at least.

Answer 3

["

This clears the console on Windows and puts the cursor at 0,0:<\/i>

var util = require('util');
util.print("\u001b[2J\u001b[0;0H");

Answer 4

This is for Linux mainly; but is also reported to work in Windows.

There is Ctrl + L in Gnome Terminal that clears the terminal. It can be used with Python, Node JS or any other REPL running in terminal. It has the same effect as clear command.

Answer 5

我正在使用 Windows CMD，这对我有用

console.clear();

Answer 6

And to clear the console while in strict mode on Windows:

'use strict';
process.stdout.write('\x1Bc'); 

Answer 7

只需在 Windows 上使用CTRL + L即可清除控制台。

Answer 8

从 Node.JS v8.3.0开始，您可以使用clear方法：

console.clear()

Answer 9

Haven't tested this on Windows but works on unix. The trick is in the child_process module. Check the documentation. You can save this code as a file and load it to the REPL every time you need it.

var exec = require('child_process').exec;

function clear(){
    exec('clear', function(error, stdout, stderr){
        console.log(stdout);
    });    
}

Answer 10

To solve problems with strict mode:

'use strict';
process.stdout.write('\x1B[2J');

Answer 11

Just use the official way:

 console.log('Blah blah blah'); // Prints "Blah blah blah" console.clear(); // Clears, or in other words, resets the terminal. console.log('You will only see this message. No more Blah blah blah...');

Answer 12

If you're using VSCode you can use CTRL + K . I know this is not a generic solution but may help some people.

Answer 13

Based on sanatgersappa's answer and some other info I found, here's what I've come up with:

function clear() {
    var stdout = "";

    if (process.platform.indexOf("win") != 0) {
        stdout += "\033[2J";
    } else {
        var lines = process.stdout.getWindowSize()[1];

        for (var i=0; i<lines; i++) {
            stdout += "\r\n";
        }
    }

    // Reset cursur
    stdout += "\033[0f";

    process.stdout.write(stdout);
}

To make things easier , I've released this as an npm package called cli-clear .

Answer 14

There is no console.clear() in node.

With ES6 JavaScript received the ''.repeat() string method , and so we can do:

console.log('\n'.repeat(1000));

which will basically print 1000 empty lines and simulate a console.clear()

Answer 15

You can use the readline module:

readline.cursorTo(process.stdout, 0, 0) moves the cursor to (0, 0).

readline.clearLine(process.stdout, 0) clears the current line.

readline.clearScreenDown(process.stdout) clears everything below the cursor.

const READLINE = require('readline');

function clear() {
    READLINE.cursorTo(process.stdout, 0, 0);
    READLINE.clearLine(process.stdout, 0);
    READLINE.clearScreenDown(process.stdout);
}

Answer 16

I couldn't get any of the above to work. I'm using nodemon for development and found this the easiest way to clear the console:

  console.log("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");

It just scrolls the console several lines so you get a clear screen for subsequent console.log commands.

Hope it helps someone.

Answer 17

["

此代码在我的 node.js 服务器控制台 Windows 7 上运行良好。<\/p>

process.stdout.write("\\\\\");<\/code><\/p>"]

Answer 18

在 mac 上，我只是简单地使用Cmd + K来清除控制台，非常方便，比在项目中添加代码来做到这一点更好。

Answer 19

Using vs code on Windows, its kinda inconsistent. This is what seems to work for me.

Clear console from package.json script:

(eg before executing your app)

{  
"scripts": {
    "clear": "node -e \"process.stdout.write('\\033c')\""
  }
}

In a file, clear the console up to the start of the script:

(Not super helpful for comparing deep logs)

console.clear()

completely obliterate all evidence of previous attempts at programming:

import { execSync } from child_process
execSync(process.platform === 'win32' ? 'cls' : 'clear', { stdio: 'inherit' })

according to the nodejs docs, setting options.stdio to 'inherit' passes the stdio stream to the parent process (ie vscode's integrated terminal), which is why this works.

Answer 20

On package.json try this:

  "nodemonConfig": {
    "events": {
      "start": "clear"
    }
  }

Answer 21

迟到了，但是如果您使用的是 powershell，则 ctrl+l 可以在 Windows 中使用 :) Powershell + Chocolatey + node + npm = 获胜。

Answer 22

Ctrl + L这是最好、最简单、最有效的选项。

Answer 23

In my case I did it to loop for ever and show in the console a number ever in a single line:

class Status {

  private numberOfMessagesInTheQueue: number;
  private queueName: string;

  public constructor() {
    this.queueName = "Test Queue";
    this.numberOfMessagesInTheQueue = 0;
    this.main();
  }

  private async main(): Promise<any> {    
    while(true) {
      this.numberOfMessagesInTheQueue++;
      await new Promise((resolve) => {
        setTimeout(_ => resolve(this.showResults(this.numberOfMessagesInTheQueue)), 1500);
      });
    }
  }

  private showResults(numberOfMessagesInTheQuee: number): void {
    console.clear();
    console.log(`Number of messages in the queue ${this.queueName}: ${numberOfMessagesInTheQuee}.`)
  }
}

export default new Status();

When you run this code you will see the same message "Number of messages in the queue Test Queue: 1." and the number changing (1..2..3, etc).