Trivial file upload service using Sinatra

trivial_file_upload_service.rb

require 'rubygems'
require 'sinatra'

require 'fileutils'

# upload with:
# curl -v -F "data=@/path/to/filename"  http://localhost:4567/user/filename

post '/:name/:filename' do
  userdir = File.join("files", params[:name])
  FileUtils.mkdir_p(userdir)
  filename = File.join(userdir, params[:filename])
  datafile = params[:data]
#  "#{datafile[:tempfile].inspect}\n"
  File.open(filename, 'wb') do |file|
    file.write(datafile[:tempfile].read)
  end
  "wrote to #{filename}\n"
end

How would that call to curl be replicated in an html form?

Take a look at aliem's fork, it seems to have an html example: https://gist.github.com/428783

Awesome, thanks! Should have searched a bit harder.