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File System Interactions

Filesystems can be interacted with the fs module as well as using the path module.

__filename and __dirname for current location

Files and directories "live" at a location which is accessible by a path.

Lets consider a simple directory structure with a few js files to see what the __filename and __dirname globally available vars do:

  • a test dir containing
    • an index.js file
    • a directory called nested, which contains
      • an index.js file
- test (dir)
    - index.js (file)
    - nested (dir)
      - index.js (files)

Here's what the js files will contain:
test/index.js

require('./nested');

console.log('test index file')

console.log({
  filename: __filename,
  dirname: __dirname
})

test/nested/index.js:

console.log('nested index file');

console.log({
  filename: __filename,
  dirname: __dirname,
});

With a terminal in the test dir, after running node ., the output will show...

nested index file
{
  filename: '/Users/my-username/Desktop/test/nested/index.js',
  dirname: '/Users/my-username/Desktop/test/nested'
}
root index file
{
  filename: '/Users/my-username/Desktop/test/index.js',
  dirname: '/Users/my-username/Desktop/test'
}

The path module helps with cross-platform paths

path is a native node module that "...provides utilities for working with file and directory paths..." (thanks node docs!).
More on path here

Tags:
node
fs
core