server.rb

require 'sinatra'

#     
before do
  puts 'before process'
end

#     
after do
  puts 'after process'
end

#          
not_found do
  '
404 you know!
'
end

get '/' do
  '
Hello World
'
end

#  views/index.erb  
get '/show' do
  erb :index
end

#  views/success.erb  
post '/submit' do
  @email = '[email protected]'
  @email2 = params['email']
  @url = request.url
  erb :success
end

server.rbファイルのあるディレクトリにディレクトリviewsを作成し、
次にviewsで、次のファイルを作成します.
index.erb

  
  


submit you form

you email : 

success.erb

this is success page
HR   ：
    ：
you url