Package Management (Linux)

How to Use the Friendly Interactive Shell (Fish) in Linux

Discover the vibrant world of the Fish shell on Linux, designed for a friendlier command-line experience. With intuitive features like syntax highlighting and auto-suggestions, this guide covers installation, customization, and essential commands to boost your productivity effortlessly!

Alex Reed

Nov 1, 2024 — 2 min read

The Fish shell is a vibrant and interactive option for enhancing your command-line experience on Linux. Thanks to its intuitive design, Fish provides valuable features like syntax highlighting, auto-suggestions, and easy-to-use configurations—solving many common command-line frustrations through efficiency and enjoyment. This tutorial will guide you through installing the Fish shell, exploring its features, and tailoring it to suit your requirements.

Installing Fish Shell on Linux

First, let's install the Fish shell on your Linux system. The steps vary slightly depending on your distribution. Here's how to do it for several popular Linux distributions:

Ubuntu/Debian:
```
sudo apt update
sudo apt install fish
```
Fedora:
```
sudo dnf install fish
```
Arch Linux:
```
sudo pacman -S fish
```
OpenSUSE:
```
sudo zypper install fish
```

After running the appropriate command for your system, start Fish by typing fish in your terminal.

Getting Started with Fish Shell

Opening Fish Shell

Once you've installed Fish, open it by entering fish into your terminal. You'll notice its eye-catching syntax highlighting, which makes commands easy to read and interact with.

Setting Fish as the Default Shell

Falling for its design and functionality? Make Fish your default shell with these steps:

Locate the Path to Fish:
```
which fish
```
Usually, the output will be something like /usr/bin/fish.
Change the Default Shell:
Use the path you found:
```
chsh -s /usr/bin/fish
```
Log out and back in to apply the changes.

Basic Usage of Fish Shell

Fish provides an array of convenient features for both regular and advanced users:

Syntax Highlighting: Quickly spots errors with immediate visual feedback.
Autosuggestions: Predicts what you type based on history, which reduces keystrokes.
2-letter Abbreviation: Simplifies commands with fewer keystrokes:
```
gbr  # Instead of typing "git branch"
```

Variables and Functions: Manage environment variables and create reusable command functions easily.

set PATH /usr/local/bin $PATH  # Temporarily modify path
function ll
    ls -lh  # Defines ll as shorthand for ls -lh
end

Managing Fish Configuration

Customize your environment by configuring files located at ~/.config/fish/config.fish. Here, you can set environment variables and define custom functions for a personalized experience.

Fish Shell Commands

Common Commands

List Files: Display directory contents using ls.
```
ls
```
Change Directory: Navigate between folders with cd.
```
cd /path/to/directory
```

Fish-Specific Commands

History Search: Find and reuse past commands quickly.
```
history
```
Editing Path: Add or change directories in your PATH.
```
set -U fish_user_paths /new/path $fish_user_paths
```

Example: Customize Your Fish Prompt

Fish’s flexible prompt system allows you to craft a unique shell prompt:

Open the configuration file:
```
nano ~/.config/fish/config.fish
```

Add a custom prompt function:

function fish_prompt
    echo -n (whoami) '@' (hostname) ' ' (prompt_pwd) ' > '
end

Save and restart your terminal to see your personalized prompt.

Recommended Fish Add-ons

Enhance Fish's capabilities with these add-ons:

Oh My Fish: A community-driven package manager for Fish, ideal for simplifying plugin and theme installations.
```
curl -L https://get.oh-my.fish | fish
```
Fzf: A quick fuzzy finder that enhances navigation through your files and directories.

Conclusion

The Friendly Interactive Shell (Fish) doesn't just promise user-friendliness; it delivers an upgraded shell experience. With features like autosuggestions and syntax highlighting, Fish offers a modern way to escape from traditional shell hassles. Use this tutorial as a starting point for mastering Fish and enhancing your productivity with essential command-line techniques.

By following this guide, you have unlocked a world of streamlined command-line operations with Fish. Discover its features, customize your setup, and see how it simplifies your tasks on Linux. Enjoy your enhanced terminal experience!