• You have a lot of CoffeeScript, Haml, Sass, Jade and Stylus ... files and you want them to be automatically compiled when you save.
• You don't want a full "IDE" like LiveReload, CodeKit or Compass.
• You like coffee --watch mode.

Install

npm install -g watcher

Command Line

Output in the same folder

watcher src/

Output in the bin/ folder

watcher -o bin/ src/

Watch a single file

watcher src/application.coffee

Output Example

Let's start the watcher, it compiles everything it finds.

22:36:30 - compiled src/index.haml
22:36:30 - compiled src/soulver.coffee
22:36:30 - compiled src/soulver.less

Oops, we made an error:

22:36:56 - compiled src/soulver.coffee
bin/soulver.js: Error: Parse error on line 2: Unexpected '''
    at Object.parseError (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/parser.js:470:11)
    at Object.parse (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/parser.js:546:22)
    at Object.compile (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/coffee-script.js:40:22)
    at /usr/local/lib/node_modules/coffee-script/lib/coffee-script/command.js:140:33
    at Socket.<anonymous> (/usr/local/lib/node_modules/coffee-script/lib/coffee-script/command.js:167:14)
    at Socket.emit (events.js:64:17)
    at Pipe.onread (net.js:348:51)

We fix the problem, save again and it goes back in order :)

22:37:15 - compiled src/soulver.coffee

Just Ctrl+C when you are done editing the files.