Send Rcon Command?

I host 3 server, I want to have the ranks all the same, sql isn't a option, in-game my admins type /rank player name, I want to send rcon commands to my other 2 servers when my admins set peoples ranks.

How to I send rcon commands?
can i send rcon commands to localhost? (127.0.0.1)
do i need to open ports to do this?

Any help is very much appreciated, i wanna get my ranks global

 

Meatiex edited, sorry.

 

Dealyise Unofficial builds and offline mode servers are not supported here.

 

Edited it, thanks for the warning.

 

Meatiex you need to enable rcon in the server.properties, and need to set a password. Optionally you can also set a port, otherwise it will default to server port + 10. A bit more info on the protocol.

 

Rcon works on all the servers, I can connect with my phone and send commands(different ports for each server)
I want to send command like i do with my phone with a plugin.
google.com/store/apps/details?id=me.jenibor.minecraftserverstatus
anyone know how? Help would be great

I found a way to do it with java script, 'll try to convert it...
https://github.com/tehbeard/node-rcon/blob/master/examples/minecraft.js
From the link above i was able to gather the code below, but it still has tons of errors in it... any help?

Code:java

Rcon rcon = new Rcon();
rcon.connect("localhost", 25575, "password", connected);
public void connected(String err, String response) {
rcon.sendCommand("op superman", function(err, response));
rcon.end();