Node.js writeStream.clearLine() 方法

writeStream.clearLine()是模块内WriteStream 类的内置应用程序编程接口，用于清除该写流对象的当前行。

句法：

writeStream.clearLine(dir[, callback])

参数：此方法将以下参数作为参数：

• dir：定义行选择的整数值。
• 回调：操作完成后调用。

返回值：如果写入对象行清除，则此方法返回布尔值 true，否则返回 false。

示例 1：文件名：index.js

Javascript

// Node.js program to demonstrate the
// writeStream.clearLine() method
 
// Importing dgram module
var dgram = require('dgram');
 
// Creating and initializing client
// and server socket
var client = dgram.createSocket("udp4");
var server = dgram.createSocket("udp4");
 
// Handling the message event
server.on("message", function (msg) {
 
  // Creating and initializing a
  // WriteStream object
  let WriteStream = process.stdout;
 
  // Clearing the line
  // by using clearLine() API
  const col = WriteStream.clearLine();
 
  // Displaying the result
  process.stdout.write(msg + col);
 
  // Exiting process
  process.exit();
})// Binding server with port
.bind(1234, () => {
});
 
// Client sending message to server
client.send("The line is clear :-  ",
    0, 26, 1234, "localhost");

输出：

The line is clear :-  true

示例 2：文件名：index.js

Javascript

// Node.js program to demonstrate the
// writeStream.clearLine() method
 
// Creating and initializing a
// WriteStream object
let WriteStream = process.stdout;
 
// Clearing the line
// by using clearLine() API
const col = WriteStream.clearLine();
 
// Displaying the result
console.log("The line is clear :-  " + col);

使用以下命令运行 index.js 文件：

node index.js

输出：

The line is clear :-  true

参考： https://nodejs.org/dist/latest-v12.x/docs/api/tty.html#tty_writestream_clearline_dir_callback