server_restarter

#!/usr/bin/env ruby
#
# usage: script/server_restarter
#
# Rails autoloading, while nice in theory, frequently doesn't work. Since Rails 2.3+
# is so fast when completely reloading the server, I wrote this script to listen to the
# given directories, and kill/restart the server when any file is changed.
#
# It's quick, simple, and it reliably reloads your application when changes are made.
#
# To install, just copy it into the scripts directory and set it to be executable.
#
# Jonathan Penn (http://www.wavethenavel.com)

POLL_DIRECTORIES = %w(app config db lib)
POLL_TIME = 0.9     # In Seconds
SERVER_COMMAND = "script/server"

# For passenger:
# SERVER_COMMAND = "touch tmp/restart.txt"

Dir.chdir(File.dirname(__FILE__)+"/..")

@states = {}

def check_for_changes
  changes = []
  Dir[*POLL_DIRECTORIES.map{|i|i+"/**/*"}].each do |file|
    unless File.symlink?(file)
      new_time = File.stat(file).mtime
      if @states[file] != new_time
        @states[file] = new_time
        changes << file
      end
    end
  end
  changes
end

def emphasized(m)
  "\e[1;1m\e[41m   \e[0m \e[1;1m\e[1m #{m} \e[0m"
end

p1 = fork { exec SERVER_COMMAND }

Signal.trap(0) { Process.kill("INT", p1) }
Signal.trap("INT") { $stderr.puts "Shutting down server_restarter"; exit }

check_for_changes

$stderr.puts "server_restarter running...watching #{@states.length} files every #{POLL_TIME} seconds."

loop do
  sleep POLL_TIME
  changes = check_for_changes
  unless changes.empty?
    $stderr.puts emphasized("Changes found...#{changes.inspect}")
    Process.kill("INT", p1)
    p1 = fork { exec SERVER_COMMAND }
  end
end