gistfile1.rb

#!/usr/bin/env ruby -wKU

@actions = Hash.new {|h,k| h[k] = []}

def tell_program(name, &block)
  @actions['songstart'] << lambda do |*args|
    IO.popen("osascript", "w") do |f|
      f.puts %Q{
        tell application "System Events"
          if exists process "#{name}" then
            tell application "#{name}"
              #{block[*args]}
            end tell
          end if
        end tell
      }
    end
  end
end

def default_message(title, artist)
  %Q|now playing \\"#{title}\\" by #{artist}|
end

tell_program "Adium" do |title, artist|
  %Q{set status message of every account to "#{default_message title, artist}"}
end

tell_program "iChat" do |title, artist|
  %Q{set status message to "#{default_message title, artist}"}
end

@actions['songfinish'] << lambda do |title, artist|
  system("say", "just listened to #{title} by #{artist}")
end

event = ARGV.first
details = {}
$stdin.each_line do |line|
  key, value = line.chomp.split('=', 2)
  details.store(key, value)
end

@actions[event].each do |action|
  action.call details['title'], details['artist']
end