Node.js JavaScript: Simulate Keypress on Server (Like a Macro)

Question

I am trying to get a node.js script to simulate a keypress, such as the up arrow or the a button. Specifically, I am trying to make a clone of Twitch Plays Pokemon. Basically, whenever a command (up, down, left, right, a, b, select, start) is sent via IRC, the server simulates a keypress, which in turn controls a gameboy emulator. So far, I have written this with the IRC module for node.js:

var config = {
    channels: ["#tron"],
    server: "irc.freenode.net",
    botName: "wyatt"
};

var irc = require("irc");

var bot = new irc.Client(config.server, config.botName, {
    channels: config.channels
});

var commandHandler = function(from, text) {
    if(text.toLowerCase() === "up"||text.toLowerCase() === "down"||text.toLowerCase() === "left"||text.toLowerCase() === "right"||text.toLowerCase() === "a"||text.toLowerCase() === "b"||text.toLowerCase() === "select"||text.toLowerCase() === "start") {
        bot.say(config.channels[0], from.toUpperCase() + " sent the " + text.toUpperCase() + " command!");
    } else {
        bot.say(config.channels[0], from.toUpperCase() + ", that wasn't a valid command!");
    }
};

bot.addListener("message", function(from, to, text, message) {
    commandHandler(from, text);
});

To run my script, I type node scriptName.js into a command prompt. I am using Windows 7.

This connects to the freenode channel #tron, which I am using for testing purposes, as it seems to be mainly dormant.

When a user inputs one of the accpted commands, it sends a message like "NIMAID sent the LEFT command!", otherwise it sends "NIMAID, that wasn't a valid command!". As it is, it works flawlessly. So all I need to do is find a way to send a keypress and the final script is just a switch statement away.

The trouble is that any references I can find by searching the internet talks about using node.js in a browser environment, with JQuery or something similar. I need to send keypresses to an emulator.

tldr: I need to send keypresses from a node.js script to an application running on the windows 7 server desktop.

Is there any way to do this?

Bucket

What run environment and emulator are you targeting? Outside of the browser world, key handling is very platform-specific. – Chinchy

As I said, I'm using a Windows 7 Professional 64 computer. I'm hoping to be able to do something like sendkeys to a particular window. That way, it wouldn't matter what emulator I'm running, as long as the key presses get to the window. If it really comes down to it though, I plan on using Visualboy Advance. – Bucket

For windows - I used node's exec function to run a python script that calls pywin32's keyboard events. For linux you can use xdotool. Here's the file where I called it. I'm using node for the program as well. – Enquire

Answer 1

I made a node module to do this too: https://github.com/kylepaulsen/kbm-robot

var robot = require("kbm-robot");

robot.startJar();

robot.press("alt")
    .press("tab")
    .sleep(100)
    .release("tab")
    .release("alt")
    .sleep(100)
    .typeString("Hello World!")
    .go()
    .then(robot.stopJar);

Mis

I tried to use this one in Ubuntu 16, and there is a bug. The stopJar() is not working. So, every time the application is started, a new jar is executed and keep in the background. After initializing a few times, the operational system starts hanging, and later, it completely freezes. – Theogony

Answer 2

Apparently, there's a win_keyboard module in the npm registry that somebody wrote to control the keyboard in Windows. You can run npm install win_keyboard and use that; it appears to do exactly what you want.

Chinchy

Thank you, this looks absolutely perfect! I don't know how I didn't find it. However, whenever I try to do var keyboard = require("win_keyboard"); I get http://pastebin.com/sNFViRj5. I honestly don't understand what that means, other than the win_keyboard library isn't working. Any help there? – Bucket

You'll need to be running the 32-bit version of Node: the 64-bit version can't call out to 32-bit extensions. (source) – Chinchy

If you really want a 64-bit version, try emailing the author and asking them to publish the module's source code: github.com/junku901 – Chinchy

Okay, so I install the 32-bit version. When I try to do var keyboard = require("win_keyboard");, it tells me it cant find the win_keyboard node. So, I do npm install win_keyboard again, and it looks like it installed. However, when I check my node_modules folder, lo and behold, it actually deleted the win_keyboard folder! When I literally copy the .node file into the script directory and do var keyboard = require("./win_keyboard");, it still doesn't find it! This is turning into a chain of more and more tedious problems, but can somebody please help me again? :) – Bucket

RobotJS will help here, see my answer above. It has 32/64bit builds and it's cross platform. – Weixel

The link is now broken – Washbowl

Answer 3

You may try an alternative to RobotJS. It is a very small and still cross platform library to send keys to your operational system called node-key-sender. I developed after getting frustrated with RobotJS and kbm-robot.

Install it with npm install --save-dev node-key-sender.

And send a text to the keyboard using:

var ks = require('node-key-sender');
ks.sendText('This is my text');

Check out the documentation page: https://www.npmjs.com/package/node-key-sender.

Theogony