Sometimes you want to know before hand which files have been added or changed since your last deploy. Maybe you have to run a migration. Assuming you're using subversion for you source control, this task will list the pending changes.
desc "List the files that would be updated or changed in a deploy." task :svn_st_up, :roles => :app do run "cd #{current_path} && " + "svn st -u" end
from my blog