fs

---

1. Read a File Synchronously

const fs = require('fs');

const data = fs.readFileSync('file.txt', 'utf8');
console.log(data);

2. Read a File Asynchronously

const fs = require('fs');

fs.readFile('file.txt', 'utf8', (err, data) => {
  if (err) throw err;
  console.log(data);
});

3. Write a File Synchronously

const fs = require('fs');

fs.writeFileSync('file.txt', 'Hello, world!', 'utf8');

4. Write a File Asynchronously

const fs = require('fs');

fs.writeFile('file.txt', 'Hello, world!', 'utf8', (err) => {
  if (err) throw err;
});

5. Append to a File Synchronously

const fs = require('fs');

fs.appendFileSync('file.txt', ' and goodbye!', 'utf8');

6. Append to a File Asynchronously

const fs = require('fs');

fs.appendFile('file.txt', ' and goodbye!', 'utf8', (err) => {
  if (err) throw err;
});

7. Rename a File Synchronously

const fs = require('fs');

fs.renameSync('old-file.txt', 'new-file.txt');

8. Rename a File Asynchronously

const fs = require('fs');

fs.rename('old-file.txt', 'new-file.txt', (err) => {
  if (err) throw err;
});

9. Copy a File Synchronously

const fs = require('fs');

fs.copyFileSync('file.txt', 'copy-of-file.txt');

10. Copy a File Asynchronously

const fs = require('fs');

fs.copyFile('file.txt', 'copy-of-file.txt', (err) => {
  if (err) throw err;
});

11. Delete a File Synchronously

const fs = require('fs');

fs.unlinkSync('file.txt');

12. Delete a File Asynchronously

const fs = require('fs');

fs.unlink('file.txt', (err) => {
  if (err) throw err;
});

13. Create a Directory Synchronously

const fs = require('fs');

fs.mkdirSync('new-directory');

14. Create a Directory Asynchronously

const fs = require('fs');

fs.mkdir('new-directory', (err) => {
  if (err) throw err;
});

15. Remove a Directory Synchronously

const fs = require('fs');

fs.rmdirSync('new-directory');

16. Remove a Directory Asynchronously

const fs = require('fs');

fs.rmdir('new-directory', (err) => {
  if (err) throw err;
});

17. Read a Directory Synchronously

const fs = require('fs');

const files = fs.readdirSync('directory');
console.log(files);

18. Read a Directory Asynchronously

const fs = require('fs');

fs.readdir('directory', (err, files) => {
  if (err) throw err;
  console.log(files);
});

19. Check if a File Exists Synchronously

const fs = require('fs');

const exists = fs.existsSync('file.txt');
console.log(exists);

20. Check if a File Exists Asynchronously

const fs = require('fs');

fs.exists('file.txt', (exists) => {
  console.log(exists);
});

21. Get File Metadata Synchronously

const fs = require('fs');

const stats = fs.statSync('file.txt');
console.log(stats);

22. Get File Metadata Asynchronously

const fs = require('fs');

fs.stat('file.txt', (err, stats) => {
  if (err) throw err;
  console.log(stats);
});

23. Create a File Stream for Reading

const fs = require('fs');

const readStream = fs.createReadStream('file.txt');
readStream.on('data', (data) => {
  console.log(data.toString());
});

24. Create a File Stream for Writing

const fs = require('fs');

const writeStream = fs.createWriteStream('file.txt');
writeStream.write('Hello, world!');
writeStream.end();

25. Pipe a File Stream

const fs = require('fs');

const readStream = fs.createReadStream('file.txt');
const writeStream = fs.createWriteStream('copy-of-file.txt');
readStream.pipe(writeStream);

26. Watch a File for Changes

const fs = require('fs');

fs.watch('file.txt', (eventType, filename) => {
  console.log(`Event type: ${eventType}`);
  console.log(`Filename: ${filename}`);
});

27. Unwatch a File

const fs = require('fs');

const watcher = fs.watch('file.txt');
watcher.close();

28. Get File Size Synchronously

const fs = require('fs');

const size = fs.statSync('file.txt').size;
console.log(size);

29. Get File Size Asynchronously

const fs = require('fs');

fs.stat('file.txt', (err, stats) => {
  if (err) throw err;
  console.log(stats.size);
});

30. Get File Modification Date Synchronously

const fs = require('fs');

const mtime = fs.statSync('file.txt').mtime;
console.log(mtime);

31. Get File Modification Date Asynchronously

const fs = require('fs');

fs.stat('file.txt', (err, stats) => {
  if (err) throw err;
  console.log(stats.mtime);
});

32. Set File Modification Date Synchronously

const fs = require('fs');

fs.utimesSync('file.txt', new Date(), new Date());

33. Set File Modification Date Asynchronously

const fs = require('fs');

fs.utimes('file.txt', new Date(), new Date(), (err) => {
  if (err) throw err;
});

34. Get File Owner Synchronously

const fs = require('fs');

const uid = fs.statSync('file.txt').uid;
console.log(uid);

35. Get File Owner Asynchronously

const fs = require('fs');

fs.stat('file.txt', (err, stats) => {
  if (err) throw err;
  console.log(stats.uid);
});

36. Set File Owner Synchronously

const fs = require('fs');

fs.chownSync('file.txt', 1000, 100);

37. Set File Owner Asynchronously

const fs = require('fs');

fs.chown('file.txt', 1000, 100, (err) => {
  if (err) throw err;
});