How to work with file paths in Node.js

The path module of Node.js provides utilities to handle and transform file and directory paths independently of the operating system.

It is a good practice to use these functions, instead of manually splitting and concatenating strings.

Also, being independent of the operating system, your code will work correctly on different operating systems, such as Windows, macOS, and Linux.

Path Module Functions

Let’s take a look at some of the most important functions of the path module, along with practical examples of how to use them.

Joining Paths

The join function of the path module is used to join various parts of a path into a single complete path.

import path from 'node:path';

const ruta1 = '/folder1';
const ruta2 = 'subfolder/file.txt';

const rutaCompleta = path.join(ruta1, ruta2);
console.log('Complete path:', rutaCompleta);

Normalizing a Path

Path normalization is important to eliminate redundancies and simplify paths. The normalize function of the path module allows you to do this easily.

import path from 'node:path';

const ruta = '/folder1//subfolder/./file.txt';
const rutaNormalizada = path.normalize(ruta);

console.log('Normalized path:', rutaNormalizada);
// Normalized path: \folder1\subfolder\file.txt

Getting the File Name

The basename function allows you to get the base name of a file from a given path.

import path from 'node:path';

const ruta = '/folder1/subfolder/file.txt';
const nombreBase = path.basename(ruta);

console.log('File name:', nombreBase);
// File name: file.txt

Getting the Directory Name

To get the directory name from a given path, you can use the dirname function.

import path from 'node:path';

const ruta = '/folder1/subfolder/file.txt';
const nombreDirectorio = path.dirname(ruta);

console.log('Directory name:', nombreDirectorio);
// Directory name: /folder1/subfolder

Getting the File Extension

With the extname function, you can get the file extension from a given path.

import path from 'node:path';

const ruta = '/folder1/subfolder/file.txt';
const extension = path.extname(ruta);

console.log('File extension:', extension);
// File extension: .txt

Converting a Relative Path to an Absolute Path

To convert a relative path to an absolute path, you can use the resolve function.

import path from 'node:path';

const rutaRelativa = '../folder1/subfolder/file.txt';
const rutaAbsoluta = path.resolve(rutaRelativa);

console.log('Absolute path:', rutaAbsoluta);
// Absolute path: C:\..whatever..\folder1\subfolder\file.txt