This can send EV3RT application with less effort.

ev3transport.rb

#!/usr/bin/env ruby
EV3MAC = '00:00:00:00:00:00'.freeze # Replace with appropriate MAC Address.
RFCOMM = '/dev/rfcomm0'.freeze

require 'open3'

module Ev3
  class << Ev3
    def connected?
      File.exist?(RFCOMM)
    end

    def connect
      return if connected?

      resault, thread = Open3.popen2e("rfcomm -r connect #{RFCOMM} #{EV3MAC}")[1..2]

      until connected? # Wait for connect, using polling.
        print "Waiting...\r"

        raise 'rfcomm: ' + resault.read unless thread.status
        sleep 0.1
      end
      puts "rfcomm started pid: #{thread.pid}"
    end

    def send_file(filename)
      raise 'ev3_not_connected' unless connected?
      system("sz \"#{filename}\"", [:out, :in] => [RFCOMM, 'r+'])
    end

    def send_file_as(srcname, dstname)
      raise 'ev3_not_connected' unless connected?
      dstpath = "/tmp/#{dstname}"
      File.symlink(File.realpath(srcname), dstpath)
      system("sz \"#{dstpath}\"", [:out, :in] => [RFCOMM, 'r+'])
      File.delete(dstpath)
    end
  end
end

def ev3_connect
  unless Ev3.connected?
    puts 'EV3 does not connected.'
    puts 'Turn on EV3 and press [Enter].'
    gets
    Ev3.connect
  end
end

# main
case ARGV.size
when 1
  ev3_connect
  Ev3.send_file(ARGV[0])
when 2
  ev3_connect
  Ev3.send_file_as(ARGV[0], ARGV[1])
else
  puts "usage: \033[1mruby " + __FILE__ + "\033[0m \033[3m\033[4mfilename\033[0m [\033[3m\033[4mdstname\033[0m]"
end

# vim: set expandtab sw=2 :