Download file in Ruby with output of the progress

download.rb

require 'net/http'
require 'pry'

def fetch(uri_str, limit = 30)
  # You should choose a better exception.
  raise ArgumentError, 'too many HTTP redirects' if limit == 0

  uri = URI(uri_str)

  use_ssl = uri.scheme == 'https' ? true : false

  Net::HTTP.start(uri.host, uri.port, use_ssl: use_ssl) do |http|
    request = Net::HTTP::Get.new uri

    http.request request do |response|
      case response
      when Net::HTTPSuccess
        total_bytes = response.content_length
        total_current = 0

        open 'large_file', 'w' do |io|
          response.read_body do |chunk|
            io.write chunk
            total_current += chunk.size
            progress = total_current.to_f / total_bytes.to_f * 100.0

            puts "Progress: %.2f%" % progress
          end
        end
      when Net::HTTPRedirection
        location = response['location']
        warn "redirected to #{location}"
        fetch(location, limit - 1)
      else
        response.value
      end
    end
  end
end

fetch(ARGV[0])