buffer

---

1. Create a Buffer from a String:

const buf = Buffer.from('Hello, world!');

2. Create a Buffer from an Array of Numbers:

const buf = Buffer.from([1, 2, 3, 4, 5]);

3. Create a Buffer from an Array of Strings:

const buf = Buffer.from(['a', 'b', 'c', 'd', 'e']);

4. Create a Buffer from a File:

const fs = require('fs');
const buf = Buffer.from(fs.readFileSync('file.txt'));

5. Convert a Buffer to a String:

const str = buf.toString();

6. Convert a Buffer to an Array of Numbers:

const arr = buf.toJSON().data;

7. Convert a Buffer to an Array of Strings:

const arr = buf.toString().split('');

8. Concatenate Buffers:

const buf1 = Buffer.from('Hello, ');
const buf2 = Buffer.from('world!');
const buf3 = Buffer.concat([buf1, buf2]);

9. Slice a Buffer:

const buf = Buffer.from('Hello, world!');
const slicedBuf = buf.slice(0, 5); // 'Hello'

10. Copy a Buffer:

const buf1 = Buffer.from('Hello, world!');
const buf2 = Buffer.alloc(buf1.length);
buf1.copy(buf2);

11. Compare Buffers:

const buf1 = Buffer.from('Hello, world!');
const buf2 = Buffer.from('Hello, world!');
const result = buf1.compare(buf2); // 0 (equal)

12. Write to a Buffer:

const buf = Buffer.alloc(10);
buf.write('Hello, world!', 0, 12); // 'Hello, world!' written at offset 0

13. Read from a Buffer:

const buf = Buffer.from('Hello, world!');
const str = buf.toString('utf8', 0, 5); // 'Hello'

14. Inspect a Buffer:

console.log(buf.inspect());

15. Fill a Buffer with a Value:

const buf = Buffer.alloc(10);
buf.fill(0); // Fill with zeros

16. Convert a Buffer to a Base64 String:

const base64Str = buf.toString('base64');

17. Convert a Base64 String to a Buffer:

const buf = Buffer.from(base64Str, 'base64');

18. Create a Buffer from a Stream:

const stream = fs.createReadStream('file.txt');
const buf = Buffer.from(stream);

19. Write a Buffer to a Stream:

const stream = fs.createWriteStream('file.txt');
buf.copy(stream);

20. Send a Buffer over a TCP Socket:

const net = require('net');
const socket = net.connect(port, host);
socket.write(buf);

21. Receive a Buffer from a TCP Socket:

const net = require('net');
const socket = net.connect(port, host);
socket.on('data', (buf) => {
  // Handle received buffer
});

22. Write a Buffer to a File:

const fs = require('fs');
fs.writeFileSync('file.txt', buf);

23. Read a Buffer from a File:

const fs = require('fs');
const buf = fs.readFileSync('file.txt');

24. Encrypt a Buffer with AES-256:

const crypto = require('crypto');
const cipher = crypto.createCipher('aes-256-cbc', 'mypassword');
const encryptedBuf = cipher.update(buf);

25. Decrypt a Buffer with AES-256:

const crypto = require('crypto');
const decipher = crypto.createDecipher('aes-256-cbc', 'mypassword');
const decryptedBuf = decipher.update(encryptedBuf);

26. Hash a Buffer with SHA-256:

const crypto = require('crypto');
const hash = crypto.createHash('sha256');
hash.update(buf);
const hashedBuf = hash.digest();

27. Sign a Buffer with RSA:

const crypto = require('crypto');
const sign = crypto.createSign('RSA-SHA256');
sign.update(buf);
const signature = sign.sign('myprivateKey');

28. Verify a Buffer with RSA:

const crypto = require('crypto');
const verify = crypto.createVerify('RSA-SHA256');
verify.update(buf);
const verified = verify.verify('mypublicKey', signature);

29. Generate a Random Buffer:

const crypto = require('crypto');
const randomBuf = crypto.randomBytes(10);

30. Shuffle a Buffer:

const crypto = require('crypto');
crypto.randomFill(buf, (err, buf) => { /* Shuffled buffer */ });

31. Zero a Buffer:

buf.fill(0, 0, buf.length);

32. Create a Buffer Pool:

const { BufferPool } = require('bufferpool');
const pool = new BufferPool();
const buf = pool.alloc(10);

33. Use a Buffer Pool with a Stream:

const { PassThrough, BufferPool } = require('stream');
const pool = new BufferPool();
const passThroughStream = new PassThrough({ objectMode: true });
passThroughStream
  .on('data', (data, enc) => { pool.release(data); })
  .on('end', () => { pool.drain(); });

34. Use a Buffer Pool with a Middleware:

const { BufferPool, Middleware } = require('express-bufferpool');
const pool = new BufferPool();
const middleware = new Middleware(pool);
app.use(middleware);

35. Use a Buffer Pool with Request/Response:

const { BufferPool } = require('koa-bufferpool');
const pool = new BufferPool();
const app = new Koa();
app.use(async (ctx, next) => {
  ctx.set('bufferpool', pool);
  await next();
});

36. Use a Buffer Pool with TCP Server:

const { BufferPool, Server } = require('net-bufferpool');
const pool = new BufferPool();
const server = new Server(pool);
server.listen(port);