rake.rb

# Display the tasks and comments.
# rake -D => :describe
# rake -T => :tasks
def display_tasks_and_comments
  displayable_tasks = tasks.select { |t|
    (options.show_all_tasks || t.comment) &&
    t.name =~ options.show_task_pattern
  }
  case options.show_tasks
  when :tasks
    width = displayable_tasks.map { |t| t.name_with_args.length }.max || 10
    if truncate_output?
      max_column = terminal_width - name.size - width - 7
    else
      max_column = nil
    end

    displayable_tasks.each do |t|
      printf("#{name} %-#{width}s  # %s\n",
             t.name_with_args,
             max_column ? truncate(t.comment, max_column) : t.comment)
    end
  when :describe
    displayable_tasks.each do |t|
      puts "#{name} #{t.name_with_args}"
      comment = t.full_comment || ""
      comment.split("\n").each do |line|
        puts "    #{line}"
      end
      puts
    end
  when :lines
    displayable_tasks.each do |t|
      t.locations.each do |loc|
        printf "#{name} %-30s %s\n", t.name_with_args, loc
      end
    end
  else
    fail "Unknown show task mode: '#{options.show_tasks}'"
  end
end