thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$ cat build.rb 
require 'compile'
require 'run'


compile
run
thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$ cat run.rb 
def run
        puts "running..."

        exec "java HelloWorldApp"

        puts "...ran"
end
thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$ ruby build.rb 
compiling...
thufir@arrakis:~/sun_tutorial$ 
thufir@arrakis:~/sun_tutorial$