#!/usr/bin/env ruby
 
# Originally by Mike Clark and Geoffrey Grosenbach.
# From http://www.pragmaticautomation.com/cgi-bin/pragauto.cgi/Monitor/StakingOutFileChanges.rdoc
#
# Runs a user-defined command when files are modified.
#
# Like autotest, but more customizable. This is useful when you want to do
# something other than run tests. For example, generate a PDF book, run
# a single test, or run a legacy Test::Unit suite in an app that also
# has an rSpec suite.
#
# Can use Ruby's Dir[] to get file glob. Quote your args to take advantage of this.
#
#  rstakeout 'rake test:recent' **/*.rb
#  => Only watches Ruby files one directory down (no quotes)
#
#  rstakeout 'rake test:recent' '**/*.rb'
#  => Watches all Ruby files in all directories and subdirectories
 
command = ARGV.shift
files = {}
 
ARGV.each do |arg|
  Dir[arg].each { |file|
    files[file] = File.mtime(file)
  }
end
 
puts "Watching #{files.keys.join(', ')}\n\nFiles: #{files.keys.length}"
 
trap('INT') do
  puts "\nQuitting..."
  exit
end
 
loop do
  sleep 1
 
  changed_file, last_changed = files.find { |file, last_changed|
    File.mtime(file) > last_changed
  }
 
  if changed_file
    files[changed_file] = File.mtime(changed_file)
    puts "=> #{changed_file} changed, running #{command}"
    puts `#{command}`
    puts "=> done"
  end
end