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Node.js: fs-extra

This module adds a few extra file system methods that aren't included in the native fs module. It is a drop in replacement for fs.

Why?

I got tired of including mkdirp, rimraf, and cp -r in most of my projects.

Installation

npm install --save fs-extra

Usage

Drop in replacement for native fs.

var fs = require('fs-extra');

Methods

NOTE: You can still use the native Node.js methods. They are copied over to fs-extra.

copy(src, dest, callback)

Copy a file or directory. The directory can have contents. Like cp -r. There isn't a synchronous version implemented yet.

Sync: (none)

Examples:

var fs = require('fs-extra');

fs.copy('/tmp/myfile', '/tmp/mynewfile', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
}); //copies file

fs.copy('/tmp/mydir', '/tmp/mynewdir', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
}); //copies directory, even if it has subdirectories or files

createFile(file, callback)

Creates a file. If the file that is requested to be created is in directories that do not exist, these directories are created. If the file already exists, it is NOT MODIFIED.

Sync: createFileSync()

Example:

var fs = require('fs-extra')
  , file = '/tmp/this/path/does/not/exist/file.txt'

fs.createFile(file, function(err) {
  console.log(err); //null

  //file has now been created, including the directory it is to be placed in
})

mkdirs(dir, callback)

Creates a directory. If the parent hierarchy doesn't exist, it's created. Like mkdir -p.

Alias: mkdirp()

Sync: mkdirsSync() / mkdirpSync()

Examples:

var fs = require('fs-extra');

fs.mkdirs('/tmp/some/long/path/that/prob/doesnt/exist', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
});

fs.mkdirsSync('/tmp/another/path');

outputFile(file, data, callback)

Almost the same as writeFile, except that if the directory does not exist, it's created.

Sync: outputFileSync()

Example:

var fs = require('fs-extra')
  , file = '/tmp/this/path/does/not/exist/file.txt'

fs.outputFile(file, 'hello!' function(err) {
  console.log(err); //null

  fs.readFile(file, 'utf8', function(err, data) {
    console.log(data); //hello!
  })
})

readJson(file, callback)

Reads a JSON file and then parses it into an object.

Alias: readJSON()

Sync: readJsonSync(), readJSONSync()

Example:

var fs = require('fs-extra');

fs.readJson('./package.json', function(err, packageObj) {
  console.log(packageObj.version); //0.1.3
});

remove(dir, callback)

Removes a file or directory. The directory can have contents. Like rm -rf.

Alias: delete()

Sync: removeSync() / deleteSync()

Examples:

var fs = require('fs-extra');

fs.remove('/tmp/myfile', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
});

fs.removeSync('/home/jprichardson'); //I just deleted my entire HOME directory.

writeJson(file, object, callback)

Writes an object to a JSON file.

Alias: writeJSON()

Sync: writeJsonSync(), writeJSONSync()

Example:

var fs = require('fs-extra');
fs.writeJson('./package.json', {name: 'fs-extra'}, function(err){
  console.log(err);
});

Roadmap to 1.0.0

This contains items that I'm considering doing. I'd love community feedback.

File system walker. I really like this one: https://github.com/daaku/nodejs-walker
File/directory tree watcher. There are quite a few.
Method to move files.
Copy sync.
Thinking about moving rimraf, ncp, and mkdirps code into this library. I'd like fs-extra to be a stable library that module authors can depend upon. A bunch of other dependencies kinda sucks for modules/libraries.
Change documentation to use the fse prefix instead of fs. This may encourage people to start using fse as a prefix and hence make their code clearer that they're not using the native fs. I'm very undecided on this one since fs-extra is a drop in replacement for the native fs.

Naming

I put a lot of thought into the naming of these function. Inspired by @coolaj86's request. So he deserves much of the credit for raising the issue. See discussion(s) here:

First, I believe that in as many cases as possible, the Node.js naming schemes should be chosen. However, there are problems with the Node.js own naming schemes.

For example, fs.readFile() and fs.readdir(): the F is capitalized in File and the d is not capitalized in dir. Perhaps a bit pedantic, but they should still be consistent. Also, Node.js has chosen a lot of POSIX naming schemes, which I believe is great. See: fs.mkdir(), fs.rmdir(), fs.chown(), etc.

We have a dilemma though. How do you consistently name methods that perform the following POSIX commands: cp, cp -r, mkdir -p, and rm -rf?

My perspective: when in doubt, err on the side of simplicity. Consider that for a moment. A directory is just a hierarchical grouping of directories and files. So when you want to copy it or remove it, in most cases you'll want to copy or remove all of its contents. When you want to create a directory, if the directory that it's suppose to be contained in does not exist, then in most cases you'll want to create that too.

So, if you want to remove a file or a directory regardless of whether it has contents, just call fs.remove(path) or its alias fs.delete(path). If you want to copy a file or a directory whether it has contents, just call fs.copy(source, destination). If you want to create a directory regardless of whether its parent directories exist, just call fs.mkdirs(path) or fs.mkdirp(path).