Keep directory in sync with remote server using Rsync and FSEvent.

watcher.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'rb-fsevent'
require 'ruby-growl'


def sync(local, host, remote, growl)

  # Construct the bash command that runs rsync.
  cmd = "rsync " +

        "--recursive " + # Sync all subdirectories.
        "--copy-links " + # include symlinked
        "--compress " + # Compress before transferring (faster)

        # Exclude stuff that you don't want to transfer.
        "--exclude '.git' " +
        "--exclude '.svn' " +

        "--delete " + # If you delete files locally,
                      # also delete remotely.

        local + " " + host + ":" + remote

  # Notify via Growl that sync is triggered.
  growl.notify("ruby-growl Notification", "Sync", "#{local} => #{host}:#{remote}")

  # Run the command.
  system cmd

end



local  = '/Users/mpj/code/web-site-player/'
host   = 'my.development.vm.machine.spotify.net'
remote = '/home/mpj/src/web-site-player/'

growl = Growl.new "localhost", "ruby-growl"
growl.add_notification "ruby-growl Notification"
growl.notify "ruby-growl Notification",
             "Started watching...",
             "#{local} => #{remote}"


# FSevents wont detect changes in subdirectories that are symlinks
# (because technically the symlink has not changed)
# so list all symliks an monitor them separately
paths = []

# Horribly unreadable command to recursively find all symlink paths in a directory:
symlinks_cmd = "find "+ local + " -type l -exec ls -l {} \\; | grep -no '\\->.*$' | cut -c 6-"
f = open("|" + symlinks_cmd)
output = f.read()
output.each_line { |path| paths.push path.sub(/\n/, '') }

# Finally, add the root directory.
paths.push local

fsevent = FSEvent.new
fsevent.watch paths do
    sync(local, host, remote, growl)
  end
fsevent.run

Why should I place this file locally?