const app = {
lines: document.getElementById('lines'),
textbox: createTextbox(),
lineTemplate: createLineTemplate(),

const socket = connect(

initial({ lines, uuid, charLimit }) {
app.uuid = uuid
app.charLimit = charLimit

added(line) {

removed(i) {

server.onclose = (ws) => {
if (ws.line) {
const i = lines.indexOf(ws.line)
lines.splice(i, 1)
server.sendToAll({ removed: i })

server.commands = {

begin(ws) {
const line = {
hash: ws.hash,
uuid: ws.uuid,
text: '',

ws.line = line
server.sendToAll({ added: line })

run() {
console.log(`Running on port ${this.port}`)

this.wss = new WebSocket.Server({
port: this.port,
verifyClient: this.verify.bind(this)

this.pruneInterval * 1000


Steven Degutis

Full-stack software developer for hire

Old-school Screen Sharing

October 12, 2010

A couple times in the past week, I’ve done pair-programming with my coworker (mentor?) Eric Smith while he was only remotely available. Since his network was not very reliable, we didn’t go the iChat route, which had failed in the past for this kind of screen-sharing task. Instead, we shared a screen session and coded in vim together. This article is just a brief explanation on how you can accomplish this as well.

For starters, it’s a good idea to have a server under your control. A good place to get one is slicehost, for $20 per month (you can also prepay them a year in advance for a discount, which is what I did).

Technically you can skip that step and use your own computer (or vice versa), so long as the other person can access it directly with an IP address and port number. (This means, if you’re running on Mac OS X, you need to have “Remote Login” enabled under System Prefrences -> Sharing.

Also, regardless of what computer you use, it’s generally a good idea to create a neutral, powerless user account that both parties can ssh into. That’s when the magic happens.

Once you have created the neutral user account, make sure to install GNU screen on it. On linux, this is usually available via a package manager (if not already installed) and on OS X you can probably install it via Homebrew, although I think it may already be bundled with the OS.

This isn’t a mandatory step, but generally, I like to put a .screenrc in the user’s home that contains 3 lines:

escape ^Tt
altscreen on
vbell off

I’m lazy and don’t want to explain what those do, just know that they’re helpful and you should probably include them in your .screenrc file as well.

Once you have screen installed and have configured your .screenrc file, ssh into the account and run screen -US <sessionname> where is the name you both will use when connecting. This command starts a `screen` session which you can simultaneously connect to multiple times from the same computer or which someone else can connect to (given they have the ability to `ssh` into the server). You've just started up a session, so play around, it's just a normal shell. Run `ls` and `pad` and whatever else.

So now that you’ve started the session, you can detach from it. There’s 2 ways to do this. The easiest, if you’re using that comes with OS X, is to just close the window or tab that it’s running in. That will simply detach from the screen session, leaving it running on your server or wherever you started it. The alternative is to press ctrl-t followed by the ‘d’ key. (That’s where the line escape ^Tt from earlier comes in handy. Note that if you didn’t set it, you will need to press ctrl-a instead of ctrl-t.)

Now that you have a detached session, you can reattach it and detach whenever you like. The screen command that I use to attach it is screen -xaA <sessionname>. There’s probably other switches you can use, but this one has not failed me yet. So ssh back into your server and run that command in order to reattach your session, and voila, you’re right where you left off before! You can even see your previous ls and pad commands from earlier!

But there’s an easier way to reattach by combining the ssh call with the screen call as so: ssh -t screen -xaA <sessionname>. (Using -t within the ssh command is necessary for this step as it creates a pseudo-tty for the duration of this command, which we need here.)

That’s all there is to it! Just have your buddy(ies?) ssh in to the same server as you at the same time, have one of you run vim and suddenly you have a shared pair-programming session from possibly thousands of miles away!

There is one part I did not mention here. It is technically possible for multiple users who are sshd into the same machine to share a screen session which one of them is running. But this is tricky and I’m not enough of a security expert to know if it actually poses a security risk, so I avoided it. But if you are curious, you can read this detailed explanation of how to get it working.

About me


My name is Steven Degutis, and I've been writing software professionally for a decade. During that time, I've written many apps and websites, quite a few technical articles, and kept up-to-date with the rapidly evolving software industry.

If you have software needs for web, mobile, or desktop, and are looking for a seasoned software professional, please reach out to me at to set up a phone call.

Work Experience

  • Self-employed – present
  • Clean Coders – 5 years
  • 8th Light – 2 years
  • Big Nerd Ranch – 1 year
  • Self-employed - 1 year


  • Web: full-stack
  • iOS (UIKit)
  • macOS (Cocoa)
  • AWS / EC2 / ELB


  • JavaScript
  • HTML5 / CSS
  • Swift
  • Objective-C
  • Clojure


  • Node.js
  • Express.js
  • React
  • Vue.js
  • Electron

Technical articles

Over the past decade, I've written a total of 172 technical articles on various programming languages, frameworks, best practices, and my own projects, as I kept up-to-date and active in the software industry.

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Here are some of the projects I'm most proud of. They were created using a variety of technologies, running on several different platforms and OSes. They're all finished products, and many of them are open source.

Website - Online Video Store

I wrote this web store for Robert "Uncle Bob" Martin, using Clojure for the back-end, and JavaScript for the front-end. Over the course of 5 years, I took the site from a simple three-page website to a full enterprise-ready business solution, with nearly 100% test coverage.

  • Clojure
  • Datomic
  • jQuery / D3.js
  • JavaScript
  • ClojureScript


macOS app - Dock Utility

I made Docks in 2009 for users who wanted to swap out icons in their Dock with a single click. Its unique functionality and design aesthetic attracted the attention of Apple, Engadget, MacWorld, and led to an acquisition of my start-up by Big Nerd Ranch.

  • Staff Pick
  • MacWorld 4/5 Rating
  • MacWorld Gem of the Year
  • Featured on


macOS app - Clojure IDE

Source Code

While working on, a website written completely in Clojure, I increased my productivity by building a custom IDE for macOS designed specifically for Clojure projects.

  • Objective-C
  • Clojure
  • C / C++
  • Cocoa
  • Themeable


macOS app - Hackable Automation

Source Code

This began as an experiment to see how many languages I could use to script a custom macOS window manager using our custom TCP protocol. Eventually it had bindings for Clojure, Ruby, Python, Go, JavaScript, CoffeeScript, Node.js, Chicken Sceme, and Racket, as well as other community additions.

  • TCP / Unix sockets
  • Custom protocol
  • Highly Scriptable
  • 10+ language bindings
  • Open source community

Bubble Maker

iOS app - Bubble simulator

This toy was made in a weekend to entertain my 1 year old daughter. It lets you create bubbles with your fingers, which then simulate physics by bumping into each other and falling.

  • SpirteKit
  • Custom art
  • Physics simulation
  • iOS
  • tvOS

Quick List

iOS app - Todo list app

When I couldn't find an app in the App Store that let me make very simple lists extremely quickly, I made one myself. I use it almost every day to organize and track my activities.

  • In-app purchases
  • Custom UI / UX
  • Social media
  • App Store artwork
  • Spring animations

Website - Personal Portfolio

Source Code

This very site itself was written from scratch in about a day. It uses best practices for modern responsive web design, and a custom build phase to compile the sources into a single HTML file.

  • Node.js
  • Pug / Jade
  • LessCSS
  • HTML5
  • WebSockets


Java app - Game

Source Code

The game 2048 (created by Gabriele Cirulli) is so fun that my kids wanted their own copy. So I wrote this version in Java 8, using JavaFx for attractive graphics and silky smooth animations.

  • Java 8
  • JavaFx
  • Modular code
  • Customizable
  • Animations


macOS app - Window Manager

Source Code

I created this app to increase my productivity by letting me move windows around in macOS using keyboard shortcuts. It grew into a community-driven highly extensible app, using Lua for its plugin system.

  • Objective-C
  • Embedded Lua
  • Plugin system
  • Fully documented
  • 5,000 GitHub stars

Website - Social Network

Implementing this elite social network gave me experience integrating both Apple Pay and credit card payments (via seamlessly into web apps, for a frictionless and pain-free payment experience.

  • Clojure
  • Elastic Beanstalk
  • PostgreSQL
  • Apple Pay


Website - Live Chatroom

Source Code

This isn't just any chatroom. In this web app, you can see what everyone is typing while they type it. I made this in order to scratch my itch for making real-time apps and games, and learned how to use WebSockets in the process.

  • JavaScript
  • WebSockets
  • Node.js
  • Vue.js
  • CSS


macOS app - Music Player

Source Code

As iTunes went through many user interface changes, I wanted an app that was consistent, intuitive, and easy to use. So I created Bahamut, a minimal music player for macOS with a custom user interface.

  • Objective-C
  • Custom UI
  • Cocoa
  • Core Data
  • AVFoundation


macOS app - Chat (IRC) Client

Source Code

This was written in 2009, before the time of Slack, when IRC was the main way for programmers to get short-term assistance from each other. Its purpose was to be a beautiful app with an emphasis on simplicity and usability over technical power.

  • Async networking
  • Core Animation
  • Core Text
  • IRC Protocol
  • UI Design


macOS app - Window Manager

Source Code

This is an app I actually use every single day. It lets you move windows with global keyboard shortcuts. Since it uses Vim-like key bindings, it should feel pretty natural to any programmer. There's no configuration needed; it Just Works™.

  • Minimalist UI
  • Simple UI
  • Vim-like Hotkeys
  • Global Hotkeys
  • Zero-configuration


macOS app - Lua window manager

Source Code

As an evolution of Phoenix, Hydra was my first attempt at embedding a full Lua virtual machine into an Objective-C app, to make a lightweight and efficient window manager that focused on speed, low memory usage, low CPU usage, and overall being gentle on laptop batteries.

  • Embedded Lua
  • Generated docs
  • Lightweight
  • Memory efficient
  • CPU efficient


macOS app - JavaScript window manager

Source Code

As an evolution of Zephyros, Phoenix was my attempt to use Cocoa's native JavaScript bindings to make a more lightweight and efficient window manager, that focused on speed, low memory usage, low CPU usage, and overall being gentle on laptop batteries.

  • JavaScriptCore
  • JavaScript API
  • Lightweight
  • Memory efficient
  • CPU efficient

Smaller projects

These may be tiny, but they're interesting technical feats.

Lua4Swift Swift framework for embedding Lua with a native Swift API.
choose Command line fuzzy-matching tool for macOS that uses a GUI
music Command line music daemon for macOS that only speaks JSON
hecto Command line text editor with an embedded Lua plugin system
ZephSharp Window manager for Windows using Clojure for scripting
management Minimalist EC2 configuration & deployment tool in Ruby.
go.assert Assertion helper package for writing tests in Go.
go.shattr Go library for printing shell-attributed strings to stdout.
OCDSpec2 Objective-C based testing framework with Xcode integration.