File system basics in nodejs

The fs.promises API is the modern way to interact with the file system in Node.js. It provides an alternative to the traditional error-first callbacks, allowing you to use Promises and Async/Await for cleaner, more readable code. 1. Why use fs.promises ? Before this API, if you wanted to read a file and then write to another, you would end up with "Callback Hell." With fs.promises , the code stays flat and follows a logical top-to-bottom flow. Key Advantages: Avoids Nesting: No more deep indentations. Better Error Handling: Use standard try/catch blocks. Built-in: No need for util.promisify anymore. 2. How to Import You can access the promises API in two ways: CommonJS: const fs = require('fs').promises; // OR const fs = require('fs/promises'); ES Modules (ESM): JavaScript import fs from 'fs/promises'; 3. Common Operations with Async/Await Reading a File The readFile method returns a promise that resolves with the file content. Using 'utf8' ensures you get a string instead of a Buffer. async function readMyFile() { try { const data = await fs.readFile('./config.json', 'utf8'); console.log(JSON.parse(data)); } catch (err) { console.error("Error reading file:", err.message); } } Writing and Appending writeFile : Replaces the file if it exists or creates a new one. appendFile : Adds data to the end of the file. async function manageLogs() { try { await fs.writeFile('log.txt', 'First Log Entry\n'); await fs.appendFile('log.txt', 'Second Log Entry\n'); console.log("File updated successfully!"); } catch (err) { console.error(err); } } Checking File Existence and Stats Instead of fs.exists (which is deprecated), you use fs.access or fs.stat . async function checkFile(path) { try { await fs.access(path); // Resolves if file exists and is accessible const stats = await fs.stat(path); console.log(`File size: ${stats.size} bytes`); } catch { console.log("File does not exist."); } } 5. Useful fs.promises Methods Method Description fs.mkdir() Creates a directory. fs.readdir() Reads the contents of a directory (returns an array of filenames). fs.rename() Renames or moves a file. fs.unlink() Deletes a file. fs.rm() Deletes a file or directory (recursively if requested).