How to get the current folder in Node

There are two ways to reference the current folder in a Node.js script:

• ./
• __dirname

Along with ./, there is ../, which points to the parent folder. They behave in the same way.

There is a big difference between the two, and picking the wrong one is a classic source of “file not found” errors.

What does each one return?

Using __dirname in a Node script will return the path of the folder where the current JavaScript file resides.

Using ./ will give you the current working directory. It will return the same result as calling process.cwd().

Say you have a script at /Users/flavio/dev/app/src/index.js, and you run it from the app folder:

cd /Users/flavio/dev/app
node src/index.js

Inside the script:

console.log(__dirname)
///Users/flavio/dev/app/src

console.log(process.cwd())
///Users/flavio/dev/app

__dirname never changes. It’s tied to the file. The working directory instead depends on where you ran the node command from.

Initially the current working directory is the path of the folder where you ran the node command, but that can be changed during the execution of your script, by using the process.chdir() API.

A pitfall with relative paths

Here’s where this bites you. Suppose index.js reads a file sitting next to it:

const data = fs.readFileSync('./config.json', 'utf8')

This works when you run node index.js from inside src. Run it from anywhere else, and Node looks for config.json in your working directory instead, and throws ENOENT: no such file or directory.

The fix is to build the path from __dirname, so it works no matter where the script is launched from:

const path = require('path')

const data = fs.readFileSync(path.join(__dirname, 'config.json'), 'utf8')

My advice: any time a script needs a file relative to itself, use __dirname. Use the working directory only when you want to act on the folder the user is in, like a CLI tool does.

The require() exception

There is just one place where ./ refers to the current file path, and it’s in a require() call. In there, ./ (for convenience) will always refer to the JavaScript file path, letting you import other modules based on the folder structure.

One last note: if you use ES modules, __dirname is not defined. Recent Node.js versions give you import.meta.dirname as the equivalent.