sinatra upload file

upload.rb

require 'sinatra'

post '/upload' do
  unless params[:file] &&
         (tmpfile = params[:file][:tempfile]) &&
         (name = params[:file][:filename])
    @error = "No file selected"
    return haml(:upload)
  end
  STDERR.puts "Uploading file, original name #{name.inspect}"
  while blk = tmpfile.read(65536)
    # here you would write it to its final location
    STDERR.puts blk.inspect
  end
  "Upload complete"
end