wait-for-change.rb

#!/usr/bin/env ruby

# The MIT License
# 
# Copyright (c) 2011 Mathias Leppich <mleppich@muhqu.de>
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
 
require 'rubygems'
require 'fssm'

if ARGV.empty?
  puts "Usage: " + __FILE__ + " DIR [ GLOB-PATTERNS, .. ]"
  puts " e.g.: " + __FILE__ + " ./ \"{dir1,dir2}/**/*.foo\""
  Process.abort 
end

Kernel.trap('INT') do
  Process.abort ">>> aborting..."
end

begin
  DIR = ARGV.shift
  PATTERNS = ARGV
  puts "<<< wait for changes in " + DIR + (!PATTERNS.empty? && " matching " + (PATTERNS * ", ") || "") + " >>>"
  FSSM.monitor(DIR, PATTERNS.empty? && "*" || PATTERNS) do
    update do |b, r|
      puts ">>> updated file '#{r}'"
      Process.exit
    end
    create do |b, r|
      puts ">>> created file '#{r}'"
      Process.exit
    end
    delete do |b, r|
      puts ">>> deleted file '#{r}'"
      Process.exit
    end
  end
rescue FSSM::CallbackError => e
  Process.exit
end