ZSH / Oh My ZSH! | Holy Grail

What is ZSH?

zsh is short for Z shell.

It is an interactive login shell initially designed in the 1990s for the Unix operating system. The Z shell is built on top of Bash and hence inherits all the original features and functions of the Bash shell and also has many other features of its own.

It is the default shell on macOS and that is why we will focus on getting it set up on your Mac machine.

Prerequisites

Homebrew foundation

Installation

By default, macOS ships with zsh located in /bin/zsh.

Install zsh through Homebrew:

brew install zsh

Install Oh My Zsh:

Oh My Zsh runs on top of the default zsh shell to provide additional features within the ~/.zshrc config file:

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

Close your terminal session after installation.

Verify Your Installation

Open a new terminal session and confirm your installation:

zsh --version

Close your terminal session, then remember to finish your

Homebrew foundation setup.

Good to Know

Upgrade Oh My Zsh

omz update

Themes for Your Shell

Oh My Zsh comes bundled with a lot of themes. The default theme is robbyrussell, but you can change it to any theme of your choice.

For a list of available themes, have a look at the Themes wiki.

Open your ~/.zshrc config file (use an IDE like Visual Studio Code)
Look for the line ZSH_THEME="robbyrussell"
Change to a theme of your choice and save the changes
In terminal, activate the changes by running:

source ~/.zshrc

Fonts for Your Shell

For enhanced prompt themes, install a patched font. Nerd Fonts is the recommended option — it includes Powerline glyphs plus thousands of additional icons.

# Install a Nerd Font via Homebrew (example: JetBrains Mono)
brew install --cask font-jetbrains-mono-nerd-font

See the Nerd Fonts website for the full list of available fonts.

Choose your desired font in Terminal preferences: Terminal > Preferences > Profiles > Text > Change Font

Plugins for Your Shell

Oh My Zsh comes bundled with many plugins (like git and docker) that only need to be listed in your ~/.zshrc. Third-party plugins need to be cloned first:

zsh-autosuggestions:

git clone https://github.com/zsh-users/zsh-autosuggestions ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions

zsh-syntax-highlighting:

git clone https://github.com/zsh-users/zsh-syntax-highlighting.git ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting

Add your plugins to ~/.zshrc:

Open your ~/.zshrc config file and look for the plugins section:

plugins=(git)

Add your additional plugins:

# too many plugins slow down shell startup
plugins=(
    git
    docker
    zsh-syntax-highlighting
    zsh-autosuggestions
)

Aliases for Your Shell

Aliases are shortcuts used to reduce the time spent on typing commands. Instead of typing the same command every time you use the terminal, you can set up an alias.

The following command reloads your terminal session:

eval exec zsh -l

Since this could be a frequent command, create an alias for it in your ~/.zshrc config file:

alias reload_session="eval exec zsh -l"

In terminal, simply run reload_session and it will execute the command for you.

Aliases are loaded in your shell environment and will be auto-detected once you’ve typed a portion of the alias and hit tab.

History Configuration

By default, ZSH keeps history but does not deduplicate it. Add these settings to your ~/.zshrc to keep history clean:

# Remove older duplicate entries when a new entry is added
setopt HIST_IGNORE_ALL_DUPS

# Avoid showing duplicates when searching history with Ctrl+R
setopt HIST_FIND_NO_DUPS

# Optional: increase history size (defaults are low)
HISTSIZE=10000
SAVEHIST=10000
HISTFILE=~/.zsh_history

These settings prevent the same command from cluttering your history. HIST_IGNORE_ALL_DUPS removes the older entry when a duplicate is added, while HIST_FIND_NO_DUPS skips duplicates during reverse search.

Troubleshooting

zshrc is Damaged

Verify if the file has a quarantine flag:

xattr <path_to_the_document>

# output:
com.apple.quarantine

Remove the quarantine flag:

xattr -r -d com.apple.quarantine <path_to_the_document>

Terminal will ask you to enter your admin/login password. Verify that the flag is removed by re-running the former command.

Resources

🔗

Oh My Zsh Wiki github.com

Official Oh My Zsh wiki with installation, configuration, and FAQ

🔗

Oh My Zsh Themes github.com

Browse the complete collection of Oh My Zsh themes

🔗

Oh My Zsh Plugins github.com

Explore available plugins to enhance your shell experience