node.js read

fs.read(fd, buffer, offset, length, position, callback);

const fs = require('fs');
const buffer = Buffer.alloc(1024); // 确保缓冲区足够大

fs.open('example.txt', 'r', (err, fd) => {
  if (err) throw err;
  fs.read(fd, buffer, 0, buffer.length, 0, (err, bytesRead, buffer) => {
    if (err) throw err;
    console.log(buffer.toString('utf8', 0, bytesRead));
    fs.close(fd, (err) => {
      if (err) throw err;
    });
  });
});

fs.open('nonexistent.txt', 'r', (err, fd) => {
  if (err) {
    console.error('Error opening file:', err);
    return;
  }
  // 继续读取操作
});

let position = 0;
fs.read(fd, buffer, 0, buffer.length, position, (err, bytesRead, buffer) => {
  if (err) throw err;
  console.log(buffer.toString('utf8', 0, bytesRead));
  position += bytesRead; // 更新读取位置
});