fs.realpath

What is fs.realpath?

The fs.realpath npm package is used to resolve the absolute path of a file or directory on the file system. It can be particularly useful in situations where you need to work with file paths that may include symbolic links or relative references.

What are fs.realpath's main functionalities?

Synchronous realpath resolution

This feature allows you to synchronously resolve the realpath of a given path, which means it blocks the Node.js event loop while completing. It's useful when you need the resolved path before proceeding with the next steps in your code.

const fs = require('fs');
const path = '/path/to/symlink/or/file';
const resolvedPath = fs.realpathSync(path);
console.log(resolvedPath);

Asynchronous realpath resolution

This feature provides an asynchronous way to resolve the realpath of a given path. It's non-blocking and uses a callback to handle the result. This is useful in most Node.js applications where non-blocking operations are preferred.

const fs = require('fs');
const path = '/path/to/symlink/or/file';
fs.realpath(path, (err, resolvedPath) => {
  if (err) throw err;
  console.log(resolvedPath);
});

Other packages similar to fs.realpath

graceful-fs

graceful-fs is a drop-in replacement for the fs module that offers improvements, including queueing up fs calls and retrying them when it's safe to do so. It includes a realpath method that works similarly to fs.realpath but with added robustness.

fs-extra

fs-extra adds file system methods that aren't included in the native fs module and adds promise support to fs methods. It includes realpath and realpathSync methods that behave similarly to those in fs.realpath, but within a more extensive suite of file system utilities.

README

fs.realpath

A backwards-compatible fs.realpath for Node v6 and above

In Node v6, the JavaScript implementation of fs.realpath was replaced with a faster (but less resilient) native implementation. That raises new and platform-specific errors and cannot handle long or excessively symlink-looping paths.

This module handles those cases by detecting the new errors and falling back to the JavaScript implementation. On versions of Node prior to v6, it has no effect.

USAGE

var rp = require('fs.realpath')

// async version
rp.realpath(someLongAndLoopingPath, function (er, real) {
  // the ELOOP was handled, but it was a bit slower
})

// sync version
var real = rp.realpathSync(someLongAndLoopingPath)

// monkeypatch at your own risk!
// This replaces the fs.realpath/fs.realpathSync builtins
rp.monkeypatch()

// un-do the monkeypatching
rp.unmonkeypatch()