Ruby Tail-recursion

Tail-recursion in ruby could be realized with some compile options for ruby VM:
 
RubyVM::InstructionSequence.compile_option = {
  :tailcall_optimization => true,
  :trace_instruction => false
}

More about Tail-recursion.

TOR: specify exit node

For specifying exit nodes for Tor connection you could add next two lines to your `/etc/tor/torrc`:

StrictExitNodes 1
ExitNodes {de},{ca},{us}