gem which sinatra-websocket
/usr/local/lib/ruby/1.9.1/yaml.rb:56:in `<top (required)>':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-websocket-0.3.0/lib/sinatra-websocket.rb
root@hiperbox-01:~# ruby /var/www/mystats.rb
/usr/local/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- sinatra-websockets (LoadError)
	from /usr/local/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
	from /var/www/mystats.rb:3:in `<main>'