How to Install oh-my-zsh and Use it with ZSH

Z Shell, or ZSH for short, is a Unix command-line interpreter developed in 1990 by Paul Falstad. We can consider ZSH an extended version of the Bourne Again Shell (BASH) because it has features similar to bash.

Over the years, ZSH has become one of the popular shells for Unix systems due to its features, flexibility, and customizability. Notable ZSH features include:

Auto command correction
Command auto-completion
Improved shell variable handling
Easy setup and shell customization

This guide will walk you through setting up the ZSH shell and installing and configuring the oh-my-zsh framework.

What Is Oh-My-Zsh?

Oh-my-zsh is a free and open-source framework for the ZSH shell. Oh-my-zsh is used to help efficiently manage and configure the ZSH shell. It comes packed with functions, themes, and plugins to improve the default ZSH shell.

Although other ZSH frameworks help manage the ZSH configuration, oh-my-zsh is the most popular and easy to configure.

In this guide, we shall test the installation of ZSH and oh-my-zsh frameworks on Ubuntu, Debian, CentOS, and OpenSUSE.

By the End of this tutorial, you will have learned how to:

Install the latest version of ZSH.
Setup oh-my-zsh framework to work with ZSH.
Install and enable a custom theme using oh-my-zsh.
Enable and use oh-my-zsh plugins.

Step 1: Install and Setup ZSH

The first step before configuring the oh-my-zsh framework is to ensure we have the ZSH shell installed. By default, ZSH does not come pre-installed in most Linux distributions, and you will need to install it manually.

ZSH is available in default Linux repositories, and you can use the default package manager for your system to install it.

On Debian/Ubuntu

sudo apt-get update
sudo apt-get install zsh

On CentOS/REHL

sudo dnf update
sudo dnf install zsh

On OpenSUSE

sudo zypper ref
sudo zypper install zsh

Ensure you have ZSH installed using the which command:

which zsh

If you have ZSH installed, you should get the path to the ZSH executable as:

/usr/bin/zsh

Step 2: Change Default Shell

The next step is to change the default shell for the current user.

Enter the command:

chsh -s $(which zsh)

chsh -s $(which zsh)
Enter the password for the current user to change the default shell.

To use the ZSH shell, log out the current user and log back in.

If you are using ZSH for the first time, you will need to set up the default configuration.

For now, select 0, which will create an empty .zshrc configuration file.

Step 3: Install and configure the oh-my-zsh framework

The next step after setting up ZSH is to install and configure the oh-my-zsh framework. The simplest way to install the oh-my-zsh framework is to use the provided installer script.

However, we need to ensure we have curl and git installed before downloading the script.

On Debian/Ubuntu

sudo apt-get install git curl

On CentOS/REHL

sudo dnf install git curl

On OpenSUSE

sudo dnf install git curl

Download and install the oh-my-zsh installation script using the command:

sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

You should see an output similar to the one shown below:

Oh-my-zsh will use the existing .zshrc file created earlier to customize the appearance and behavior of ZSH.

Install and enable Custom theme (Powerlevel10k).

By default, oh-my-zsh will apply the “robbyrussell” theme. Although its appearance may vary depending on the distribution, it will typically look as shown:

ZSH also comes with other default themes stored in the ~/.oh-my-zsh/themes directory.

You can apply each theme by editing the configuration file, as we will see in this article.

If the theme you wish to use is not installed in the themes directory by default, you can download it and configure it.

In this example, we will install the powerlevel10k theme.

Clone the powerlevel10k theme repository:

git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k

The command will download the powerlevel10k theme in the ~/.oh-my-zsh/themes directory.

To change the default theme to powerlevel10k, edit the .zshrc configuration:

vim .zshrc

Locate the ZSH_THEME entry and set its value to powerlevel10k as shown:

ZSH_THEME="powerlevel10k/powerlevel10k”

Save the file and close the editor.

Apply the changes by reloading the ZSH configuration:

source .zshrc

Follow the powerlevel10k configuration wizard to set up your prompt as you see fit.

Using Custom Plugins

Oh-my-zsh provides a plethora of plugins to enhance the terminal experience. The default plugins are in the ~/.oh-my-zsh/plugins directory.

To enable an oh-my-zsh plugin, edit the .zshrc configuration and add the plugin name in the plugin’s entry.

For example, to enable the git, docker, and npm plugins, we can set the plugin’s entry as:

vim .zshrc
plugins=(git docker npm)

Save and close the file.

Apply the changes:

source .zshrc

You can now use the enabled plugins’ commands and features. Consider the documentation for each plugin to learn the available commands.

Conclusion

This guide provides detailed instructions on how to install and configure the oh-my-zsh framework on Linux.