How to install Oh-My-ZSH

ZSH is a powerful alternative to Linux Bash offering a lot of features like auto-completion (I like this so much), plugins and even themes.

Once installed, two articles take it further: Beyond the Monolith - Organizing Your ZSH Workflow Like a Pro to keep your .zshrc from becoming a monster, and ZSH Functions - Customizing Your Shell for Docker Management.

The idea here is to empower your Linux console: improve the command line (f.i. new aliases out-of-the-box) and make the look and feel even better.

I've been using Oh My ZSH for years; let's see how to install it, followed by discovering some features.

Where We're Going​

This is my prompt once Zsh, Oh-My-Zsh and the Powerlevel10k theme are in place:

At a glance I know I'm in my blog folder, that it's a Git repository, that I'm on branch main and that ?1 means one untracked or modified file is waiting on my computer, not yet pushed to GitHub. No command typed, no git status run: the information is simply there, refreshed at every prompt.

Why it's worth the ten minutes​

• Oh-My-Zsh is a framework, not a theme. It ships hundreds of aliases and functions out of the box, so you get value before configuring anything.
• The prompt becomes a dashboard. Folder, repository, branch and pending-changes count are permanently displayed, which is exactly the state you keep checking manually.
• Autocompletion is on another level. TAB lists sub-folders, command flags and Git branches, instead of just completing a file name.

Seeing It in Action with Docker​

Before touching your ~/.zshrc, spin up a throwaway container and play with Oh-My-Zsh for real.

Here is the Dockerfile I prepared. It installs Oh-My-Zsh unattended and also pre-builds a small playground: a deep folder tree to try cd ... on, and a git repository with a commit and an untracked file so gst has something to show:

Build and run it:

$ docker build -t zsh-demo .
[+] Building 22.1s (8/8) FINISHED
✔ exporting to image
$ docker run --rm -it zsh-demo
🐳 root ~/demo/a/b/c/d/e/f #

You land directly inside /root/demo/a/b/c/d/e/f — six folders deep, git repo already initialized. Try the features from the next section right away:

$ cd ......
🐳 root ~/demo/a #
$ gst
On branch main
Untracked files:
notes.txt
$ take /tmp/scratch
🐳 root /tmp/scratch #

cd ...... (six dots) jumps up five parents in one go. gst shows the untracked notes.txt without you typing git status — it works from any depth inside the repo, since Git walks up to find .git on its own. take creates /tmp/scratch and drops you inside it. Press TAB after cd to see folder autocompletion in action.

Installation​

The installation is quite easy, just three commands:

$ sudo apt-get update && sudo apt-get install zsh
$ chsh -s /usr/bin/zsh
$ sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"▋

With the last instruction, you'll be asked if you want to change the default shell to zsh; simply answer Yes.

And very quickly you can see a change in your console:

The first change concerns the prompt. Right now, I'm in my blog folder and it's a git repository. So, Oh-My-ZSH is showing me that info and, on top, the current branch I'm working on (branch master here).

Nice but, we can do much better.

Time to install a template engine called Powerlevel10k (https://github.com/romkatv/powerlevel10k). If you'd rather try it in a throwaway container before touching your machine, read Customize your Linux prompt with Powerlevel 10k. In the next paragraph, I'll install Powerlevel10k on my computer, so let's go ahead.

Powerlevel10k​

Installation is easy too, just run git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k in your console. You'll then download the template.

The second action to take is to edit the ~/.zshrc file. Since I'm using VSCode, I just start VSCode, press CTRL+O and open the ~/.zshrc file.

Search for ZSH_THEME and set the value to powerlevel10k/powerlevel10k.

The last thing is to close your current Linux console and start a new one. The first time, you'll get the Powerlevel10k configuration wizard:

Just answer all the questions and when it's time to define your preference, just select the option you like the most.

When done, here is what my prompt will look like:

And this is so much better (and much prettier). Quickly, I know I'm in my blog folder, that it's a Git repository, that I'm on branch main and ?1 means I've one untracked or modified file on my computer and not yet pushed to the central repo (GitHub here).

At the right, we can see I'm connected as root on my machine. It's shown in red just to indicate I have root access.

Customizing the prompt​

Ok, let's remove that part since, yeah, it's my home computer, it's normal here I'm root since I've just one local account and that information is then meaningless to me.

Powerlevel10k has great documentation, and by reading How do I add username and/or hostname to prompt?, we learn how to remove it the same way.

Just edit the ~/.p10k.zsh file, search for POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS and then find its context entry and comment out the line. Save the file, open a new console and bingo, the right side of the prompt no longer contains the username — you're now looking at the prompt shown at the top of this article.

Some features I use daily​

You might think these features are not needed but the fact is I'm using them so much in my daily work.

For instance, take /tmp/new_folder will create the folder if not yet present and will jump in it.

Be honest, take /tmp/new_folder is easier and faster than mkdir -p /tmp/new_folder && cd $_ no?

A second, so stupid but so valuable feature is cd .. followed by two or three or ... dots.

Imagine you're in the folder /tmp/new_folder/a/b/c/d/e/f and you want to use cd .. to jump back to parent a. Using ZSH, I can just type cd ...... and that's cool. cd .. jumps to the first parent, cd ... to the grandparent and so on.

There is also one key feature with ZSH and it's TAB. Imagine you're in a folder having multiple sub-folders. Just type cd (the space is really important) and press TAB. You'll then get the list of sub-folders. Navigate between suggestions by using TAB and press ENTER to select one.

Then, continue, press TAB again and you'll be able to select a sub-folder and you can continue like that.

TAB is then used by ZSH for auto-completion. Let's try something else: head - followed by TAB. As you can see below, I'll get the list of command line flags I can use, I can navigate still using TAB and continue to type my command line.

In terms of aliases, one I use several times a day is gst for git status. You can retrieve the list of all aliases for Git in your /root/.oh-my-zsh/plugins/git/git.plugin.zsh file. A nice one is gwip to commit all your changes as work in progress allowing you to store your current work, checkout another branch (f.i. to work on an issue) and when done, checkout back your feature branch and retrieve your work. Easy.

And for sure, there are more — I probably don't even know they're part of ZSH anymore.

Conclusion​

Three commands install Zsh and Oh-My-Zsh, a git clone and one ZSH_THEME line bring the Powerlevel10k prompt, and a single commented-out entry in ~/.p10k.zsh removes the noise you don't need. From there the gains are permanent: take, cd ..., TAB completion and gst are typed dozens of times a day without you thinking about them.

There is much, much more, like plugins. Next up, zsh-autosuggestions and zsh-syntax-highlighting, two must-haves once Oh-My-Zsh is in place.