gistfile1.rb

fernando@endor ~/workspace/cubox/sinatra-test $ cat main.rb

require 'sinatra'                                                                   
require 'slim                                                                   

get '/' do "Hello"
                                                                  
end                                                                                                                  

get '/:task' do
  @task = params[:task]
  slim :task
end

fernando@endor ~/workspace/cubox/sinatra-test $ cat Gemfile
source 'https://rubygems.org'

gem "sinatra"
gem "slim"
fernando@endor ~/workspace/cubox/sinatra-test $ ls views/
total 8.0K
-rw-r--r-- 1 fernando users 105 Sep 11 14:18 layout.slim
-rw-r--r-- 1 fernando users  23 Sep 11 14:19 task.slim

fernando@endor ~/workspace/cubox/sinatra-test $ cat views/layout.slim 
doctype html
html
  head
    meta charset="utf-8"
    title Just Do It
  body
    h1 Layout
    == yield
fernando@endor ~/workspace/cubox/sinatra-test $ cat views/task.slim 
Hello
  = params[:task]