How can I send binary data from Sinatra?

Question

I want to send binary data from a Sinatra application so that the user can download it as a file.

I tried using send_databut it gives me an undefined method 'send_data'

How could I achieve this?

I could write the data to a file and then use send_filebut I would rather avoid doing this.

Answer 1

you can just return binary data:

get '/binary' do
  content_type 'application/octet-stream'
  "\x01\x02\x03"
end

Answer 2

I did it like this:

get '/download/:id' do
  project = JSON.parse(Redis.new.hget('active_projects', params[:id]))
  response.headers['content_type'] = "application/octet-stream"
  attachment(project.name+'.tga')
  response.write(project.image)
end

Answer 3

The current version of Sinatra has a way to stream data:

get '/' do
  stream do |out|
    out << "It's gonna be legen -\n"
    sleep 0.5
    out << " (wait for it) \n"
    sleep 1
    out << "- dary!\n"
  end
end

Source: http://www.sinatrarb.com/intro#Streaming%20Responses

Answer 4

I used something like this:

require 'sinatra'

set :port, 8888
set :bind, '0.0.0.0'
filename = 'my_firmware_update.bin'

get '/' do
    content_type 'application/octet-stream'
    File.read(filename)
end