Watchy
Run commands when paths change.
Install
You'll need to install Node.js to use Watchy. Node comes packaged with npm, which is Node's package manager, and the preferred method of installing Watchy. After installing Node, simply type
npm install -g watchyand you should have the watchy command available!
Usage
Usage: watchy [options] -- command arg1 arg2 ...
Run commands when paths change.
Options:
-V, --version output the version number
-d, --debounce [seconds] trigger a change at most every [seconds] seconds
-k, --keep-alive restart the process if it exits
-p, --use-polling use file polling even if fsevents or inotify is available
-r, --restart [string] send [string] to STDIN to restart the process
-R, --no-restart-after-signal disable process restart after being signaled and exited
-s, --silent only output errors
-S, --no-init-spawn prevent spawn when the watcher is created
-t, --shutdown-signal [signal] use [signal] to shut down the process (default: "SIGTERM")
-T, --reload-signal [signal] use [signal] to reload the process (defaults to shutdown signal)
-w, --watch [pattern] watch [pattern] for changes, can be specified multiple times
-W, --wait [seconds] send SIGKILL to the process after [seconds] if it hasn't exited
-h, --help output usage information
The watch patterns are extglob format.
Examples
# The simple case
watchy -w 'lib/**/*' -- say "The lib directory changed."
# Piping works as well
watchy -w 'styles/**/*.less' -- bash -c "lessc styles/main.less | autoprefixer -o .tmp/styles/main.css"
# Keep a process alive, restarting it as soon as it exits or "server.js"
# changes.
watchy -kw server.js -- node server.js
# Watch every file except dotfiles, the node_modules folder, and JSON files.
# NOTE: Listen to as few files as possible for better performance.
watchy -w . -i '/\.|/node_modules|\.json$' -- node server.js
# Tick tock!
watchy -ks -- bash -c 'date && sleep 1'
# Tick tock (annoying version)!
watchy -ks -- bash -c 'say "In case you were wondering, it is `date`" && sleep 5'
# $WATCHY_ACTION and $WATCHY_PATH are passed to the process.
watchy -w '**/*' -- bash -c 'echo $WATCHY_ACTION $WATCHY_PATH'
# => modified /Users/casey/Documents/code/watchy/README.mdNote: If you're using
watchyfor help with preprocessing, I'd recommend checking out my cogs project that is highly optimized for that case with in-memory processed file caching, directives, AMD support, and much more.
SIGTERM
By default, watchy will send SIGTERM to the running process after a change
and wait for it to exit gracefully. By sending the --wait|-W n option, you can
tell watchy to forcefully SIGKILL the process after n seconds. In general,
you should try to clean up connections in your processes like so:
process.on('SIGTERM', function () {
server.close();
db.disconnect();
redis.quit();
// etc...
});Node API
As of 0.9.0 watchy exposes a Node.js API.
const watchy = require('watchy');
watchy({
patterns: ['js/**/*.js', 'css/**/*.css'],
onError: error => console.error(error),
onChange: ({action, path}) => console.log(action, path),
usePolling: true // defaults to `false`, but will fallback when fsevents are not available
}).catch(er => {
console.error(er);
process.exit(1);
});