Exploring Node.js Core Libraries

Topic Outline (30-min)

1. Overview of Node.js Core Libraries:

   • Core libraries are built into Node.js and do not require installation via npm.

   • Key libraries include:

     • fs (File System): Manage file operations like reading, writing, and appending.

     • http: Create and manage HTTP servers and handle requests.

     • stream: Handle and manipulate streaming data like files or network responses.

2. Working with the fs Module for File Operations:

   • Read a file:

     javascript코드 복사const fs = require('fs');
     fs.readFile('example.txt', 'utf8', (err, data) => {
       if (err) throw err;
       console.log('File content:', data);
     });

   • Write to a file:

     javascript코드 복사fs.writeFile('output.txt', 'Hello, Node.js!', (err) => {
       if (err) throw err;
       console.log('File written successfully');
     });

   • Append to a file:

     javascript코드 복사fs.appendFile('output.txt', '\nAppended content', (err) => {
       if (err) throw err;
       console.log('Content appended successfully');
     });

3. Introduction to the http Module for Creating Servers:

   • Create a simple HTTP server:

     javascript코드 복사const http = require('http');
     
     const server = http.createServer((req, res) => {
       res.writeHead(200, { 'Content-Type': 'text/plain' });
       res.end('Hello, HTTP Server!');
     });
     
     server.listen(3000, () => {
       console.log('Server is running at http://localhost:3000');
     });

4. Using Streams for Efficient Data Handling:

   • Streams allow handling large data piece by piece without loading the entire content into memory.

   • Example: Reading a file with a stream:

     javascript코드 복사const fs = require('fs');
     
     const readStream = fs.createReadStream('largeFile.txt', 'utf8');
     readStream.on('data', (chunk) => {
       console.log('Received chunk:', chunk);
     });