Added _ that is te result of the previous command.

lib/repl.js

@@ -41,6 +41,7 @@ function readline (cmd) {
       // Scope the readline with exports.scope to provide "local" vars
       with (exports.scope) {
         var ret = eval(buffered_cmd);
+        exports.scope['_'] = ret;
         printValue(ret);
       }