Refactor; use LaunchAgent service rather than Login Items + .app shim

FileWatcher.js

@@ -0,0 +1,61 @@
+/*jslint node: true */
+var util = require('util-enhanced');
+var fs = require('fs');
+var logger = require('winston');
+
+/** new FileWatcher(filepath: string, delay: number, onchange: ())
+
+Watch a filepath for changes, calling `onchange` when the file changes.
+
+Mostly a wrapper around fs.watch / fs.FSWatcher, but with some debounce.
+
+delay
+  Milliseconds to wait before calling onchange again. A delay of 0 means
+  onchange will be called immediately every time the file changes (no debounce).
+*/
+function FileWatcher(filepath, delay, onchange) {
+  this.filepath = filepath;
+  this.onchange = onchange;
+  this.delay = delay;
+}
+
+/** FileWatcher#start()
+
+Start the underlying watcher.
+
+Debounces for a period of `delay` seconds; executes on the immediate end.
+*/
+FileWatcher.prototype.start = function() {
+  var self = this;
+  var last_called = -1;
+
+  this.fs_watcher = fs.watch(this.filepath, {persistent: true})
+  .on('change', function(event, filename) {
+    // filename may not actually be supplied
+    // TODO: check last modified stats?
+    // if (curr.mtime.valueOf() != prev.mtime.valueOf() ||
+    //   curr.ctime.valueOf() != prev.ctime.valueOf()) {
+    var since_last = Date.now() - last_called;
+    logger.debug('Saw %s on %s (%dms since last call)', event, self.filepath, since_last);
+    if (since_last >= self.delay) {
+      self.onchange();
+      last_called = Date.now();
+    }
+    else {
+      logger.debug('Not firing onchange due to debounce (%d < %d)', since_last, self.delay);
+    }
+  })
+  .on('error', function(err) {
+    logger.error('Error in fs.watch: %s', err);
+  });
+};
+
+/** FileWatcher#stop()
+
+Close the underlying watcher.
+*/
+FileWatcher.prototype.stop = function() {
+  this.fs_watcher.close();
+};
+
+module.exports = FileWatcher;

README.md

@@ -1,46 +1,62 @@
 # fs-change
 
-Node.js process to monitor changes to specified files or directories, and execute
-some specified action in response.
+Monitor files or directories and execute actions in response to changes.
 
-`fs-change` accepts two command line arguments:
+File watchers and triggered actions are specified in a single file.
 
-* `--config` where to read which files to watch.
-    - By default, fs-change reads settings from `~/.fs-change`, i.e., from the user's home directory.
-    - But the location of this file can be specified using this command line flag, e.g., `--config /opt/local/watching`.
-* `--log` where to write the log file.
-    - Defaults to `~/Library/Logs/fs-change.log` (which can easily be viewed with Console.app)
 
-## Installation
-
-For Mac OS X:
-
-    # cd into this directory
-    touch ~/.fs-change
-    ./index.js install
+## Watch file format
 
-This will add the `FSChange.app` application to the list of applications in your "login items,"
-so that it gets started automatically.
-
-After running `./index.js install`, either restart your computer or double click `FSChange.app`.
-
-## `~/.fs-change` format
+The location of this file defaults to `~/.fs-change`.
 
 Each line has a glob (or simple file) on the left of a colon, and a command on
 the right.
 
 The command on the right will have the following keywords available:
 
-- {file}, the fullpath of the matching file (usually just the string to the left
-  of the colon).
-- {basename}, the shortname of {file}, without path or extension.
-- {dirname}, the directory containing {file}.
+- `{file}`, the fullpath of the matching file (usually just the string to the
+  left of the colon).
+- `{basename}`, the shortname of {file}, without path or extension.
+- `{dirname}`, the directory containing {file}.
 
-## `~/.fs-change` example
+Example:
 
     /Users/chbrown/work/mailmaster/static/css/site.less: cd {dirname} && lessc -C site.less site.css
     /Volumes/sshfs_drive/app4/static/*.less: cd {dirname} && lessc -C {basename}.less {basename}.css
 
+
+## Configuration
+
+The following environment variables can be used to configure the behavior of
+the file listener.
+
+* `OSX` [default: unset]
+
+  If set, fs-change will log to the NotificationCenter as well as STDOUT/STDERR.
+
+* `CONFIG` [default: '~/.fs-change']
+
+  Specify the path to the configuration file specifying the files to watch.
+
+* `DEBUG` [default: unset]
+
+  If set, fs-change will set the log level to DEBUG.
+
+
+## Installation
+
+    fs-change print-launch-agent > ~/Library/LaunchAgents/npmjs.fs-change.plist
+    launchctl load ~/Library/LaunchAgents/npmjs.fs-change.plist
+
+The generated LaunchAgent will log to `~/Library/Logs/fs-change.log`, which
+you can view in `Console.app`.
+
+To uninstall:
+
+    launchctl unload ~/Library/LaunchAgents/npmjs.fs-change.plist
+    rm ~/Library/LaunchAgents/npmjs.fs-change.plist
+
+
 ## TODO
 
 * If some file does not exist, the script will continue to try the other files,
@@ -50,6 +66,7 @@ The command on the right will have the following keywords available:
   should retry the filepath in question.
 * Add documentation for macro syntax (`& /regex/flags/ => replacement`)
 
+
 ## License
 
-Copyright © 2012–2013 Christopher Brown. [MIT Licensed](LICENSE).
+Copyright 2012-2015 Christopher Brown. [MIT Licensed](http://opensource.org/licenses/MIT).

bin/fs-change

@@ -0,0 +1,15 @@
+#!/usr/bin/env node
+/*jslint node: true */
+var command = process.argv[2];
+
+if (command == 'print-launch-agent') {
+  require('../commands/print-launch-agent');
+}
+else if (command == 'service') {
+  require('../commands/service');
+}
+else {
+  console.error('Unrecognized command: %s', command);
+  console.error('  Available commands: print-launch-agent, service');
+  process.exit(1);
+}

commands/print-launch-agent.js

@@ -0,0 +1,12 @@
+#!/usr/bin/env node
+var fs = require('fs');
+var path = require('path');
+
+var filepath = path.join(__dirname, '..', 'launch-agent.plist');
+var template = fs.readFileSync(filepath, {encoding: 'utf8'});
+
+var string = template.replace(/\$\{(\w+)\}/g, function(match, group, index) {
+  return process.env[group];
+});
+
+process.stdout.write(string);

commands/service.js

@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+var path = require('path');
+var child_process = require('child_process');
+var _ = require('underscore');
+var logger = require('winston');
+
+var config = require('../config');
+var FileWatcher = require('../FileWatcher');
+
+if (process.env.OSX) {
+  var NotificationCenterTransport = require('winston-notification-center');
+  logger.add(NotificationCenterTransport, {title: 'File system watcher'});
+}
+
+logger.level = process.env.DEBUG ? 'debug' : 'info';
+
+var config_filepath = (process.env.CONFIG || '~/.fs-change').replace(/^~/, process.env.HOME);
+
+var file_watchers = [];
+var restart = function() {
+  logger.debug('Stopping %d FileWatchers', file_watchers.length);
+  _.invoke(file_watchers, 'stop');
+  file_watchers.length = 0;
+  config.loadFileWatchers(config_filepath, function(err, new_file_watchers) {
+    if (err) {
+      logger.error('Error reading config file: %s', err);
+      process.exit(1);
+    }
+
+    Array.prototype.push.apply(file_watchers, new_file_watchers);
+
+    logger.debug('Starting %d FileWatchers', file_watchers.length);
+    _.invoke(file_watchers, 'start');
+  });
+};
+
+var config_watcher = new FileWatcher(config_filepath, 2000, restart);
+config_watcher.start();
+restart();