Terminal Kaio-Ken

Update 1: There are some issues with certain FontAwesome icons due to a mixup with the font codepoints. After speaking with folks who maintain the powerlvl9k project, a new release in the `next` branch has all the fixes.

Update 2: Added details about customizing your prompt for a richer developer environment.

In this post, I wish to elaborate on my command-line terminal setup and share what I believe is a productive, highly-utilitarian and not to mention gorgeous terminal experience. As a computer scientist/engineer, I spent more time using the terminal than a regular GUI. And if you’re Unix oriented like me, you will know that using the terminal is so much more efficient and nimble than using the mouse.

To begin with, I have eschewed the standard Bash shell in favor of the much more powerful ZSH shell. ZSH offers much more comprehensive file globbing and auto-complete features than Bash and is really nifty in how it uses its history to recall old commands you may wish to repeat. I highly recommend going through this slide-deck to gain an understanding of what ZSH can accomplish for you.

However, ZSH on its own is not enough. To really make our experience amazing, let me introduce you to the delightful Oh-My-ZSH, a community-driven project  which provides plugin and themes for the ZSH shell, and boy are they useful. To install ZSH, use the instructions here and for OMZ, all you need to do is run:

# An easy shell script to install Oh-My-ZSH. I use the wget version since it is more ubiquitous.
sh -c "$(wget https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)"

Now time for some styling! If you are a Dragon Ball Z fan like myself and some of my friends, the title of this post will bring back a lot of memories, specifically, this meme –


The theme I most prefer is powerlevel9k. Based on the Powerline theme, it combines functionality with a good dose of fanciness, while making a nice little reference to a beloved anime character. Installing it though is not as straightforward as the above steps have been. To install the theme,  we first have to download it and add it to the right folder:

$ git clone https://github.com/bhilburn/powerlevel9k.git ~/.oh-my-zsh/custom/themes/powerlevel9k

Then, we open up the ~/.zshrc file and specify the theme


This uses the basic Oh-My-ZSH framework to install the theme, though you are more than welcome to use Antigen or ZPM if you are aware of them.

At this point, if you open your terminal, you may find some glaring deficiencies. This is because we haven’t yet set up the powerline fonts needed to render all the smooth jazz of this theme. Let’s do that. First we download the latest versions of the symbol font and the fontconfig files:

wget https://github.com/powerline/powerline/raw/develop/font/PowerlineSymbols.otf
wget https://github.com/powerline/powerline/raw/develop/font/10-powerline-symbols.conf

After this we need to create the font folder to store these files and create the font cache

  mkdir ~/.fonts

We can now move the font file to the above folder

mv PowerlineSymbols.otf ~/.fonts/

and generate the font-cache

fc-cache -vf ~/.fonts/

Note you may have to provide root privileges for the above step.

Finally, install the font config file:

mv 10-powerline-symbols.conf ~/.config/fontconfig/conf.d/

Now that we have the powerline fonts set up, restart your terminal. Doesn’t it look fabulous?

If you want a more fully featured font set for a developer, I recommend checking out Adobe’s Source Code Pro and the Hack font. To install, just copy the fonts to the ~/.fonts directory and run fc-cache -fv

If the theme seems a bit off, for example the arrows aren’t quite aligned, this is mostly a problem with your terminal emulator. Go to the terminal emulator’s preferences and select the Hack or Source Code Pro theme and it should be fixed.

But wait, there’s more! Since we’ve already made this much progress, why not go one more step ahead and add some amazing font icons from FontAwesome? This can be easily accomplished using the instructions here. I am not specifying them verbatim here since the repository is still undergoing active development and the install instructions are subject to change in the near future.

Your terminal should now look something like this:


I generally dislike redundancy and useless information. Seeing my name on the prompt is exactly that, so why I not eschew it in favor of more meaningful information such as what Python virtualenv is currently active, or what Ruby version you are using? Let’s do that.

In your ~/.zshrc, you have to add some minor commands custom to powerlvl9k. These are:

POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(virtualenv pyenv rvm rbenv go_version nvm status history time)

It should be pretty straightforward to understand what each item in the parentheses corresponds to. This is my setup, so feel free to omit things you don’t need. You can checkout what prompt elements are available here. While you’re there, be sure to look up how to stylize your prompt as well to get your creative juices flowing.

Finally, this is what you get:terminal

As a closing thought, one very useful OMZ plugin I use is zsh-syntax-highlighting which updates the color of the terminal text when it is correct, thus ensuring your commands are valid before you hit enter. This plugin can easily be installed using the plugins list in the ~/.zshrc and specifying the plugin exactly as above in the parentheses.

I hope you enjoy your new super-saiyan terminal experience. If you don’t particularly like it, the Oh-My-ZSH page has dozens of themes to choose from, and if you have the time, you can go ahead and create your own theme.


The Sound Of Commits

Well, all I can say is that I’ve been busy. How busy you ask? Let this post answer it for you.

I had come across the Github API a while back and ever since I have been contemplating ways to use the data provided by the API in a meaningful way. After weeks of brain-wracking, I finally hit upon the idea that why not render the commits for a year long period as musical notes? If you have a Github account, you might have noticed in your “Repositories” tab there is a wonderful little visualizer that has blocks of varying green colorations, showing your Github activity over the past 1 year. Why not audiolize it?

So first things first, I head over to Github’s API docs. Now the beauty of Github’s API is that it to read user and public repository a.k.a. repo information, I don’t need to sign in. That enabled me to write the whole thing in client side Javascript and not worry about Cross Origin Resource Sharing (CORS) since the audiolization would be hosted on my website. This made my task much, much easier (and more hassle-free for the user). Some quick jQuery setup and custom wrappers to the AJAX calls had me pulling the data in a jiffy.

The next step was preparing the data, i.e. getting the commits from the last one year for a user across repos and grouping them by date. Github allowed me to limit the data returned to the past 1 year, but grouping it was still an issue. That is where moment.js comes in. This intuitive and feature-rich library gave me all that I needed to manipulate and compare the date-time signatures on each commit as well as taught me the standard for representing dates and times. Couple this with a few articles on Javascript promises and closures (Lisp throwback!!) and I have my data ready to be audiolized.

A small digression: For all my difficulty with JS and its weak-typing model, the fact that Lisp has inspired JS and that JS allows me to come from a functional programming school of thought, made my code really clean and easy to work with. I was strictly against creating a global variable to store and work on the final data in the JS file since side effects from functions could mess up the data and be really hard to track down and fix. Functional programming, which by design avoids side affects on your data, really helped me out and JS’ closures really sold me to the language.

Now for the music. Musical Instrument Digital Interface or MIDI is the de facto standard for rendering music and this is no different on the web. Here is where I found this amazing project called MIDI.js on, you guessed it, Github! I forked the repo so I had my own version to play around with, and after some digging around since the documentation was substandard, I had attached MIDI musical notes to my commit data.

After some quick HTML and CSS where I set up the web page, I finally published it to the web. Sharing with people via Facebook and Twitter helped get some good feedback on it. You can find it here. Be sure to try it out, especially if you have a Github account. Seeing all my Github activity rendered as music was a joy like no other and I was glad to be able to help others see that joy as well.

Let me play you a song of your commits. If you have any suggestions, do feel free to comment.


Seeing Spaces by Bret Victor

A workspace to help us better understand the things we build so we have a more scientific approach to whatever we do.

I so need to do this in my work space!!