Sinatra File Upload

controller

    if params[:file]
    path = './public/tmpfile'
    File.open(path,'w'){ |f| f.write(params[:file][:tempfile].read) }
    @original = File.open(path).read
    end

view

    %form{:action=>'/', :method=>'post', :enctype=>'multipart/form-data'}
      %input{:type=>'file', :name=>'file'}
      %input{:type=>'submit', :value=>'POST'}