The Node.js path module

The path module provides a lot of very useful functionality to access and interact with the file system.

There is no need to install it. Being part of the Node.js core, it can be used by simply requiring it:

const path = require('path')

This module provides path.sep which provides the path segment separator (\ on Windows, and / on Linux / macOS), and path.delimiter which provides the path delimiter (; on Windows, and : on Linux / macOS).

These are the path methods:

path.basename()

Return the last portion of a path. A second parameter can filter out the file extension:

require('path').basename('/test/something') //something
require('path').basename('/test/something.txt') //something.txt
require('path').basename('/test/something.txt', '.txt') //something

path.dirname()

Return the directory part of a path:

require('path').dirname('/test/something') // /test
require('path').dirname('/test/something/file.txt') // /test/something

path.extname()

Return the extension part of a path

require('path').extname('/test/something') // ''
require('path').extname('/test/something/file.txt') // '.txt'

path.format()

Returns a path string from an object, This is the opposite of path.parse
path.format accepts an object as argument with the follwing keys:

• root: the root
• dir: the folder path starting from the root
• base: the file name + extension
• name: the file name
• ext: the file extension

root is ignored if dir is provided
ext and name are ignored if base exists

// POSIX
require('path').format({ dir: '/Users/joe', base: 'test.txt' }) //  '/Users/joe/test.txt'

require('path').format({ root: '/Users/joe', name: 'test', ext: 'txt' }) //  '/Users/joe/test.txt'

//WINODWS
require('path').format({ dir: 'C:\\Users\\joe', base: 'test.txt' }) //  'C:\\Users\\joe\\test.txt'

path.isAbsolute()

Returns true if it's an absolute path

require('path').isAbsolute('/test/something') // true
require('path').isAbsolute('./test/something') // false

path.join()

Joins two or more parts of a path:

const name = 'joe'
require('path').join('/', 'users', name, 'notes.txt') //'/users/joe/notes.txt'

path.normalize()

Tries to calculate the actual path when it contains relative specifiers like . or .., or double slashes:

require('path').normalize('/users/joe/..//test.txt') //'/users/test.txt'

path.parse()

Parses a path to an object with the segments that compose it:

• root: the root
• dir: the folder path starting from the root
• base: the file name + extension
• name: the file name
• ext: the file extension

Example:

require('path').parse('/users/test.txt')

results in

{
  root: '/',
  dir: '/users',
  base: 'test.txt',
  ext: '.txt',
  name: 'test'
}

path.relative()

Accepts 2 paths as arguments. Returns the relative path from the first path to the second, based on the current working directory.

Example:

require('path').relative('/Users/joe', '/Users/joe/test.txt') //'test.txt'
require('path').relative('/Users/joe', '/Users/joe/something/test.txt') //'something/test.txt'

path.resolve()

You can get the absolute path calculation of a relative path using path.resolve():

path.resolve('joe.txt') //'/Users/joe/joe.txt' if run from my home folder

By specifying a second parameter, resolve will use the first as a base for the second:

path.resolve('tmp', 'joe.txt') //'/Users/joe/tmp/joe.txt' if run from my home folder

If the first parameter starts with a slash, that means it's an absolute path:

path.resolve('/etc', 'joe.txt') //'/etc/joe.txt'