Watch a folder for changes using node.js, and print file paths when they are changed

Question

I\'m trying to write a node.js script that watches for changes in a directory of files, and then prints the files that are changed. How can I modify this script so that it w

Answer 1

try hound:

hound = require('hound')

// Create a directory tree watcher.
watcher = hound.watch('/tmp')

// Create a file watcher.
watcher = hound.watch('/tmp/file.txt')

// Add callbacks for file and directory events.  The change event only applies
// to files.
watcher.on('create', function(file, stats) {
  console.log(file + ' was created')
})
watcher.on('change', function(file, stats) {
  console.log(file + ' was changed')
})
watcher.on('delete', function(file) {
  console.log(file + ' was deleted')
})

// Unwatch specific files or directories.
watcher.unwatch('/tmp/another_file')

// Unwatch all watched files and directories.
watcher.clear()

It will execute once file was change

Answer 2

Try Chokidar:

var chokidar = require('chokidar');

var watcher = chokidar.watch('file or dir', {ignored: /^\./, persistent: true});

watcher
  .on('add', function(path) {console.log('File', path, 'has been added');})
  .on('change', function(path) {console.log('File', path, 'has been changed');})
  .on('unlink', function(path) {console.log('File', path, 'has been removed');})
  .on('error', function(error) {console.error('Error happened', error);})

Chokidar solves some of the crossplatform issues with watching files using just fs.

Answer 3

Why not just use the old fs.watch? Its pretty straightforward.

fs.watch('/path/to/folder', (eventType, filename) => {
console.log(eventType);
// could be either 'rename' or 'change'. new file event and delete
// also generally emit 'rename'
console.log(filename);
})

For more info and details about the options param, see Node fs Docs