Fish: A Friendly Shell with Built-in Beautification

While Bash and Zsh dominate the Linux shell landscape, Fish (Friendly Interactive Shell) offers a refreshing alternative with its focus on user-friendliness and out-of-the-box features. This article will guide you through installing Fish, configuring it, and enhancing its functionality with plugins to create a visually appealing and efficient terminal experience.

1. Installing Fish:

Fish is readily available in most distribution repositories. Install it using your package manager:

• Debian/Ubuntu: sudo apt-get update && sudo apt-get install fish
• Fedora/CentOS: sudo dnf install fish
• Arch Linux: sudo pacman -S fish

Once installed, make Fish your default shell:

Bash

chsh -s /usr/bin/fish

Log out and back in, or restart your terminal.

2. Fish’s Built-in Beautification:

Fish comes with many features that enhance the shell’s look and feel without needing external plugins. These include:

• Syntax Highlighting: Fish highlights commands as you type, indicating valid and invalid syntax.  
• Autosuggestions: Fish suggests commands based on your history, similar to zsh-autosuggestions.
• Tab Completions: Fish offers intelligent tab completions that are context-aware.
• Web-Based Configuration: Fish provides a web interface for configuring settings and themes. Access it by typing fish_config in your terminal.

3. Configuring Fish:

• Themes:
  • Use fish_config to browse and select themes.
  • The web interface allows you to preview themes and customize colors.  
• Configuration Files:
  • Fish configuration is stored in ~/.config/fish/.
  • ~/.config/fish/config.fish is the primary configuration file, where you can add functions, aliases, and environment variables.
  • ~/.config/fish/functions/ is where you can store custom functions.

4. Installing Plugins with Fisher:

While Fish has many built-in features, plugins can extend its functionality. Fisher is a popular plugin manager for Fish.  

• Installing Fisher:

Bash

curl -sL https://git.io/fisher | source && fisher install jorgebucaran/fisher

• Installing Plugins:

Use fisher install <plugin_name> to install plugins. Here are a few recommended plugins:

• fzf:
  • A general-purpose fuzzy finder that can be integrated with Fish for enhanced file and command search.  
  • fisher install jethrokuan/fzf
• z:
  • Jumps to frequently used directories.
  • fisher install jethrokuan/z
• Done:
  • Displays a notification when long-running commands complete.  
  • fisher install edc/done

5. Customizing the Prompt:

Fish’s prompt can be customized by creating or modifying functions in ~/.config/fish/functions/.

• Example Custom Prompt:

Create a file named fish_prompt.fish in ~/.config/fish/functions/ with the following content:

Code snippet:

function fish_prompt
    set -l cwd (pwd | sed "s|^$HOME|~|")
    set -l git_branch (git branch --show-current 2>/dev/null)

    set_color brblue
    echo -n "$cwd"

    if test -n "$git_branch"
        set_color bryellow
        echo -n " ($git_branch)"
    end

    set_color normal
    echo -n "\n❯ "
end

This example displays the current working directory, the Git branch (if in a Git repository), and a prompt symbol.

6. Nerd Fonts:

Like Zsh, Fish can benefit from Nerd Fonts to display icons and symbols correctly. Download and install a Nerd Font from a source like Nerd Fonts’ GitHub repository.

7. Advantages of Fish:

• User-Friendly Syntax: Fish’s syntax is more intuitive than Bash’s.
• Out-of-the-Box Features: Fish provides many essential features without requiring plugins.
• Web-Based Configuration: fish_config makes configuration easy.
• Intelligent Autosuggestions and Completions: Fish’s suggestions and completions are highly accurate and helpful.

Fish offers a modern and enjoyable terminal experience with its built-in features and easy plugin management. By following these steps, you can create a visually appealing and highly functional Fish shell that enhances your productivity.