Shell & Environment

Shanios ships a fully configured Zsh environment with modern UX features enabled out of the box. All shell configuration lives in your home directory and persists across every OS update and rollback.

Default Shell Stack

| Tool | Role | |------|------| | Zsh | Default shell for all users | | Starship | Cross-shell prompt with git, language runtime, exit-code, and timing info | | McFly | Neural-network command history search (replaces Ctrl+R) | | FZF | Fuzzy finder — integrated for Ctrl+T (files) and Alt+C (cd) | | zsh-syntax-highlighting | Fish-style inline syntax colouring (green = valid, red = invalid) | | zsh-autosuggestions | Ghost-text suggestions from history; press → or End to accept | | zsh-history-substring-search | Up/Down arrow searches history by substring, not just prefix | | zsh-completions | Tab completions for git, systemctl, podman, flatpak, nix-env, shani-deploy, and more |

Bash and Fish are also installed if you prefer them.

Changing Your Shell

chsh -s /bin/bash    # switch to Bash
chsh -s /bin/fish    # switch to Fish
chsh -s /bin/zsh     # switch back to Zsh (default)

Log out and back in for the change to take effect.

Customising Zsh

nano ~/.zshrc
source ~/.zshrc   # reload without restarting the shell

Starship Prompt

Starship shows by default: current directory, git branch/status, active Python virtualenv, Node.js version (in Node projects), Rust toolchain version (when Cargo.toml is present), exit code of last command (when non-zero), and command duration for long-running commands.

nano ~/.config/starship.toml
starship help

McFly History Search

McFly replaces Ctrl+R with a context-aware, exit-code-aware history search that learns from your usage patterns. Everything runs on-device — no data leaves your system.

# Press Ctrl+R to open McFly
# Type to filter; Enter to select; Ctrl+C to cancel

# McFly database location (grows more useful over time)
ls ~/.local/share/mcfly/

FZF Integration

FZF is integrated into Zsh for three keybindings:

| Keybinding | Action | |-----------|--------| | Ctrl+R | History search (McFly takes precedence; FZF is fallback) | | Ctrl+T | Fuzzy file finder — inserts selected path at cursor | | Alt+C | Fuzzy cd — jump to any subdirectory |

# Use fzf in scripts
ls | fzf
fzf --preview 'cat {}'

# Select a git branch to checkout
git branch | fzf | xargs git checkout

Pre-Installed CLI Tools

File Search and Navigation

rg "search term"           # ripgrep — fast recursive search
rg --type py "import"      # search only Python files
fd "filename"              # fd — modern find replacement
fd -e py                   # find by extension

File Viewing

bat file.py                # bat — cat with syntax highlighting
eza -la --git              # eza — modern ls with git status

System Monitoring

htop                       # interactive process viewer
fastfetch                  # system information summary
ncdu                       # interactive disk usage analyser

Text Processing

echo '{"key": "value"}' | jq .    # jq — JSON processor

Compression

7z a archive.7z file.txt
tar xzf archive.tar.gz
unzip archive.zip

Shell Configuration Files

~/.zshrc                     — Zsh configuration (plugins, aliases, env vars)
~/.bashrc                    — Bash configuration
~/.profile                   — login shell config (shared between shells)
~/.config/starship.toml      — Starship prompt configuration
~/.local/share/mcfly/        — McFly history database
~/.config/environment.d/     — session environment variables (Wayland/X)

All of these are in @home — never touched by OS updates or rollbacks.

Environment Variables

# Shell-specific (Zsh)
nano ~/.zshrc
export EDITOR=vim
export PATH="$HOME/.local/bin:$PATH"

# Session environment (Wayland/X sessions)
# ~/.config/environment.d/my-vars.conf
EDITOR=nvim
MOZ_ENABLE_WAYLAND=1

# System-wide
sudo nano /etc/environment

Nix Package Manager

Nix is pre-installed on the dedicated @nix subvolume. Install CLI tools without root — they survive all OS updates and rollbacks:

# Add channel (required before first install)
nix-channel --add https://nixos.org/channels/nixpkgs-unstable nixpkgs
nix-channel --update

# Install packages
nix-env -iA nixpkgs.ripgrep
nix-env -iA nixpkgs.bat
nix-env -iA nixpkgs.lazygit
nix-env -iA nixpkgs.zoxide

# List installed
nix-env -q

# Upgrade all
nix-env -u '*'

Tmux

Tmux is pre-installed:

tmux new -s work          # start named session
Ctrl+B then %             # split horizontally
Ctrl+B then "             # split vertically
Ctrl+B then D             # detach (session keeps running)
tmux ls                   # list sessions
tmux attach -t work       # reattach

Configuration lives in ~/.tmux.conf.