Read TXT/DAT file and Parsing before saving to database (mysql)

Question

I have an application in Ruby on Rails whose one of the features is to read a text file with the following extensions "TXT/DAT", for this, I need a simple page (only an input field(file) and a button of Submit) for sending the file, the file itself has several lines that are answers of a proof, the file is like this:

"EEECBEBABABCEEAACDAEDABCCDDBEAEAEAEABBDBACCACDEBBEDCBEDEBBDCCDCDABBEADDBACEDCEABCDBCCECEED"

each letter is the answer to a question, and the table in the database will receive each record in a question/answer row

what I’ve done so far

Route file:

get "pages/envio"
post "pages/envio"

view:

<%= form_tag '/pages/envio' ,multipart: true do %>
    <label for="file">File to Upload</label> <%= file_field_tag :file %>
    <div><%= submit_tag 'Process' %></div>
<% end %>

controller:

def envio
    @file = params[:file]
    if(@file.respond_to?(:read))
      File.read("#{@file}".to_s, 'r') do |file|
        while line = file.gets
          @gabarito = line[0..line.rstrip.size].split(//)
        end
      end
    elsif(@file.respond_to?(:path))
      File.open(@file) do |file|
        @file = file
      end
      render :envio
    end
end

any idea?