The fs (file system) module provides APIs to interact with the file system. Use the fs/promises API with async/await for clean, non-blocking code.
Common operations: reading files, writing files, appending, and checking if a file exists.
Node.js
Beginner
10 min read
Reading and Writing Files
Example
const fs = require('fs/promises');
const path = require('path');
async function fileDemo() {
const filePath = path.join(__dirname, 'data.txt');
// Write a file (creates or overwrites):
await fs.writeFile(filePath, 'Hello, Node.js!\nLine 2\n', 'utf8');
console.log('File written.');
// Read a file:
const content = await fs.readFile(filePath, 'utf8');
console.log('Content:', content);
// Append to a file:
await fs.appendFile(filePath, 'Line 3 appended.\n', 'utf8');
// Get file stats:
const stats = await fs.stat(filePath);
console.log('Size:', stats.size, 'bytes');
console.log('Modified:', stats.mtime);
// Check existence (try/catch is the modern way):
try {
await fs.access(filePath);
console.log('File exists');
} catch {
console.log('File does not exist');
}
// Delete the file:
await fs.unlink(filePath);
console.log('File deleted.');
}
fileDemo().catch(console.error);