Node.js 中 fs 模块的高级用法实例详解

const fs = require('fs');
// 创建可读流
const readStream = fs.createReadStream('largeFile.txt', 'utf8');
// 监听数据事件
readStream.on('data', (chunk) => {
  console.log('Received chunk:', chunk.length);
});
// 监听结束事件
readStream.on('end', () => {
  console.log('File reading completed');
});
// 监听错误事件
readStream.on('error', (err) => {
  console.error('Error reading file:', err);
});

const fs = require('fs');
// 创建可写流
const writeStream = fs.createWriteStream('output.txt');
// 写入数据
writeStream.write('Hello, world!\n');
writeStream.write('This is a stream example.\n');
// 结束写入
writeStream.end();
// 监听完成事件
writeStream.on('finish', () => {
  console.log('File writing completed');
});
// 监听错误事件
writeStream.on('error', (err) => {
  console.error('Error writing file:', err);
});

const fs = require('fs');
// 创建可读流和可写流
const readStream = fs.createReadStream('source.txt');
const writeStream = fs.createWriteStream('destination.txt');
// 使用管道复制文件
readStream.pipe(writeStream);
// 监听完成事件
writeStream.on('finish', () => {
  console.log('File copied successfully');
});
// 监听错误事件
readStream.on('error', (err) => {
  console.error('Error reading file:', err);
});
writeStream.on('error', (err) => {
  console.error('Error writing file:', err);
});

const fs = require('fs');
// 监视文件变化
const watcher = fs.watch('example.txt', (eventType, filename) => {
  console.log(`Event type: ${eventType}`);
  if (filename) {
    console.log(`File changed: ${filename}`);
  }
});
// 关闭监视器
setTimeout(() => {
  watcher.close();
  console.log('Watcher closed');
}, 10000); // 10 秒后关闭

const fs = require('fs');
// 监视文件变化
fs.watchFile('example.txt', { interval: 1000 }, (curr, prev) => {
  if (curr.mtime !== prev.mtime) {
    console.log('File modified');
  }
});
// 停止监视
setTimeout(() => {
  fs.unwatchFile('example.txt');
  console.log('Stopped watching file');
}, 10000); // 10 秒后停止

const fs = require('fs').promises;
async function readFile() {
  try {
    const data = await fs.readFile('example.txt', 'utf8');
    console.log('File content:', data);
  } catch (err) {
    console.error('Failed to read file:', err);
  }
}
readFile();

const fs = require('fs').promises;
async function writeFile() {
  try {
    await fs.writeFile('example.txt', 'Hello, world!', 'utf8');
    console.log('File written successfully');
  } catch (err) {
    console.error('Failed to write file:', err);
  }
}
writeFile();

const fs = require('fs');
const path = require('path');
async function readDirRecursive(dir) {
  const files = await fs.promises.readdir(dir);
  for (const file of files) {
    const filePath = path.join(dir, file);
    const stats = await fs.promises.stat(filePath);
    if (stats.isDirectory()) {
      await readDirRecursive(filePath); // 递归读取子目录
    } else {
      console.log('File:', filePath);
    }
  }
}
readDirRecursive('./').catch((err) => {
  console.error('Failed to read directory:', err);
});

const fs = require('fs');
const path = require('path');
async function deleteDirRecursive(dir) {
  const files = await fs.promises.readdir(dir);
  for (const file of files) {
    const filePath = path.join(dir, file);
    const stats = await fs.promises.stat(filePath);
    if (stats.isDirectory()) {
      await deleteDirRecursive(filePath); // 递归删除子目录
    } else {
      await fs.promises.unlink(filePath); // 删除文件
      console.log('Deleted file:', filePath);
    }
  }
  await fs.promises.rmdir(dir); // 删除空目录
  console.log('Deleted directory:', dir);
}
deleteDirRecursive('./temp').catch((err) => {
  console.error('Failed to delete directory:', err);
});