Node.js fs。Dirent.isBlockDevice()方法

原文:https://www . geesforgeks . org/node-js-fs-dirent-is blockdevice-method/

fs。Dirent.isBlockDevice() 方法是类 fs 的内置应用编程接口。文件系统模块中的目录,用于检查特定目录是否描述了块设备。 语法:

const dirent.isBlockDevice()

参数:此方法不接受任何参数。 返回值:如果特定方向描述阻塞设备,则该方法返回真,否则返回假。 下面的程序说明了fs . dirent . isblockdevice()方法在 Node.js: 中的使用示例 1: 文件名:index.js

java 描述语言

// Node program to demonstrate the
// dirent.isBlockDevice() method
const fs = require('fs');

// Initiating async function
async function stop(path) {

  // Creating and initiating directory's
  // underlying resource handle
  const dir = await fs.promises.opendir(path);

  // Synchronously reading the directory's
  // underlying resource handle using
  // readSync() method
  for(var i =0 ; i <=3 ; i ++ ){

  // Checking if the particular dirent
  // is blocked device or not by using
  // isBlockDevice() method
  const value = (dir.readSync()).isBlockDevice();

  // Display the result
  console.log(dir.readSync());
  console.log(value);

  }
}

// Catching error
stop('./').catch(console.error);

使用以下命令运行 index.js 文件:

node index.js

输出:

Dirent { name: 'cert.cer', [Symbol(type)]: 1 }
false
Dirent { name: 'certificate1.cer', [Symbol(type)]: 1 }
false
Dirent { name: 'filename.txt', [Symbol(type)]: 1 }
false
Dirent { name: 'GFG.java', [Symbol(type)]: 1 }
false

示例 2: 文件名:index.js

java 描述语言

// Node program to demonstrate the
// dirent.isBlockDevice() method
const fs = require('fs');

// Initiating async function
async function stop(path) {

    // Creating and initiating directory's
    // underlying resource handle
    const dir = await fs.promises
        .opendir(new URL('file:///F:/'));

    // Synchronously reading the directory's
    // underlying resource handle using
    // readSync() method
    for (var i = 0; i <= 3; i++) {

        // Checking if the particular
        // dirent is blocked device or not
        // by using isBlockDevice() method
        const value = (dir.readSync())
                        .isBlockDevice();

        // Display the result
        console.log(dir.readSync());
        console.log(value);
    }
}

// Catching error
stop('./').catch(console.error);

使用以下命令运行 index.js 文件:

node index.js

输出:

Dirent { name: 'adonis_auth_api', [Symbol(type)]: 2 }
false
Dirent { name: 'Android Template', [Symbol(type)]: 2 }
false
Dirent { name: 'Calander', [Symbol(type)]: 2 }
false
Dirent { name: 'first-app', [Symbol(type)]: 2 }
false

注意:以上程序不会在在线 JavaScript 和脚本编辑器上运行。 参考:https://nodejs . org/dist/latest-v 12 . x/docs/API/fs . html # fs _ dirent _ isblockdevice