Package Exports

node-watch

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (node-watch) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

node-watch

A wrapper and enhancements for fs.watch.

Installation

npm install node-watch

Example

var watch = require('node-watch');

watch('file_or_dir', { recursive: true }, function(evt, name) {
  console.log('%s changed.', name);
});

Now it's fast to watch deep directories on macOS and Windows, since the recursive option is natively supported except on Linux.

// watch the whole disk
watch('/', { recursive: true }, console.log);

Why?

Some editors will generate temporary files which will cause the callback function to be triggered multiple times.
The callback function will only be triggered once on watching a single file.
~~Missing an option to watch a directory recursively.~~
Recursive watch is not supported on Linux or in older versions of nodejs.
Keep it simple, stupid.

Options

The usage and options of node-watch are compatible with fs.watch.

persistent: Boolean (default true)
recursive: Boolean (default false)
encoding: String (default 'utf8')

Extra options

filter: RegExp | Function

Return that matches the filter expression.

// filter with regular expression
watch('./', { filter: /\.json$/ });

// filter with custom function
watch('./', { filter: f => !/node_modules/.test(f) });

Events

The events provided by the callback function is either update or remove, which is less confusing to fs.watch's rename or change.

watch('./', function(evt, name) {

  if (evt == 'update') {
    // on create or modify
  }

  if (evt == 'remove') {
    // on delete
  }

});

Watcher object

The watch function returns a fs.FSWatcher like object as the same as fs.watch (>= v0.4.0).

var watcher = watch('./', { recursive: true });

watcher.on('change', function(evt, name) {
  // callback
});

watcher.on('error', function(err) {
  // handle error
});

// close
watcher.close();

// is closed?
watcher.isClosed()

List of methods

.on
.once
.emit
.close
.listeners
.setMaxListeners
.getMaxListeners

Extra methods

.isClosed detect if the watcher is closed

Known issues

Windows, node < v4.2.5

Failed to detect remove event
Failed to get deleted filename or directory name

Misc

1. Watch multiple files or directories in one place

watch(['file1', 'file2'], console.log);

2. Customize watch command line tool

#!/usr/bin/env node

// https://github.com/nodejs/node-v0.x-archive/issues/3211
require('epipebomb')();

var watcher = require('node-watch')(
  process.argv[2] || './', { recursive: true }, console.log
);

process.on('SIGINT', watcher.close);

Monitoring chrome from disk:

$ watch / | grep -i chrome

Alternatives

License

MIT