Node.js File System

Node.js File System

Introduction
The Node.js File System (fs) module is a built-in module that provides an interface for working with the file system in a Node.js application. It allows developers to perform various file-related operations, such as reading, writing, updating, and deleting files.

Importing the fs Module
To use the fs module in your Node.js application, you need to import it using the require function:

javascript
const fs = require('fs');

Reading a File
To read the contents of a file, you can use the fs.readFile method. This method takes the file path and an optional encoding parameter as arguments and returns the file content in a callback function.

javascript
const filePath = 'example.txt';

fs.readFile(filePath, 'utf8', (err, data) => {
  if (err) {
    console.error('Error reading the file:', err);
    return;
  }
  console.log('File content:', data);
});

Writing to a File
To write data to a file, you can use the fs.writeFile method. This method takes the file path, data to be written, and an optional encoding parameter as arguments.

javascript
const filePath = 'output.txt';
const dataToWrite = 'This is the data to be written to the file.';

fs.writeFile(filePath, dataToWrite, 'utf8', (err) => {
  if (err) {
    console.error('Error writing to the file:', err);
    return;
  }
  console.log('Data written successfully.');
});

Updating a File
To update the contents of a file, you can use the fs.appendFile method. This method appends data to the end of the file. It takes the file path, data to be appended, and an optional encoding parameter as arguments.

javascript
const filePath = 'log.txt';
const dataToAppend = 'This is the new data to be added to the file.';

fs.appendFile(filePath, dataToAppend, 'utf8', (err) => {
  if (err) {
    console.error('Error appending data to the file:', err);
    return;
  }
  console.log('Data appended successfully.');
});

Deleting a File
To delete a file, you can use the fs.unlink method. This method takes the file path as an argument and removes the file from the file system.

javascript
const filePath = 'fileToDelete.txt';

fs.unlink(filePath, (err) => {
  if (err) {
    console.error('Error deleting the file:', err);
    return;
  }
  console.log('File deleted successfully.');
});

Conclusion
The Node.js File System module provides a powerful set of methods to interact with the file system in a Node.js application. With these methods, you can read, write, update, and delete files efficiently, making it a fundamental part of file-related operations in Node.js.