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

Bash and Fish are also installed if you prefer them — both ship with a Starship-enabled prompt and McFly history search in their skeleton config (~/.bashrc_shani, ~/.config/fish/config.fish), though the Zsh-only plugins above (syntax highlighting, autosuggestions, history-substring-search) are not mirrored there.

Terminal Emulator

The default terminal app differs by edition — both run the same shell stack above.

• KDE Plasma: Konsole, pre-installed. Yakuake (a drop-down/quake-style variant of Konsole) is also pre-installed — press F12 to toggle it from anywhere.
• GNOME: GNOME Console, pre-installed.
• COSMIC: COSMIC Terminal, pre-installed.

Any terminal emulator you install separately (via Flatpak, Nix, etc.) uses the same Zsh config and prompt — the shell environment isn't tied to a specific terminal app.

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 (truncated to the repo root), 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 — the shipped config sets min_time = 1 (millisecond), so the duration shows for almost every command, not just long-running ones.

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/

Default configuration (set in ~/.zshrc, and mirrored in ~/.bashrc_shani / ~/.config/fish/config.fish):

MCFLY_FUZZY=true              # fuzzy matching instead of exact substring
MCFLY_RESULTS=20              # number of results shown
MCFLY_INTERFACE_VIEW=BOTTOM   # results list anchored to the bottom of the screen
MCFLY_RESULTS_SORT=LAST_RUN   # most-recently-run commands surface first

Override any of these in your shell's rc file before the mcfly init line.

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

ripgrep (rg) is present on KDE Plasma only, pulled in transitively by KTextEditor's search-in-files feature (ripgrep-all depends on it) — not deliberately curated, and absent on GNOME. fd is not pre-installed on either edition. The standard POSIX tools always work:

grep -r "search term" .    # recursive text search
find . -name "filename"    # find by name
plocate filename           # indexed filename search — see Storage

For a consistent experience across editions, install both via Nix: nix-env -iA nixpkgs.ripgrep nixpkgs.fd.

File Viewing

bat and eza (modern cat/ls alternatives) are also not pre-installed — only standard cat/less/ls are. Install via Nix if wanted: nix-env -iA nixpkgs.bat nixpkgs.eza.

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
unrar x archive.rar          # extract a RAR archive (extraction only — RAR is proprietary)
lrzip -o archive.lrz file    # long-range compression, best ratio on large/redundant files
lzop -o file.lzo file        # fast, low-ratio compression — optimised for speed over size

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. The one exception is /etc/environment.d/90-shani.conf (sets the system-wide EDITOR=micro default) — it lives on the read-only root, so overriding it means setting the same variable in ~/.config/environment.d/ or your shell rc, not editing it in place.

Environment Variables

Shanios sets one system-wide default out of the box: EDITOR=micro, via a drop-in at /etc/environment.d/90-shani.conf. This is read by systemd user sessions (not just login shells), so it applies to sudoedit, visudo, crontab -e, and any tool that shells out with $EDITOR set — override it per-user rather than editing the drop-in directly, since it lives on the read-only root and any local edit would be lost on the next OS update.

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

# Session environment (Wayland/X sessions) — overrides the system-wide default
# ~/.config/environment.d/my-vars.conf
EDITOR=nvim
MOZ_ENABLE_WAYLAND=1

# System-wide (traditional PAM-read file, separate mechanism from environment.d)
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 vertically (panes side-by-side)
Ctrl+B then "             # split horizontally (panes stacked)
Ctrl+B then D             # detach (session keeps running)
tmux ls                   # list sessions
tmux attach -t work       # reattach

Configuration lives in ~/.tmux.conf.

See Also

• System Config — /etc overlay, locale, hostname, kernel parameters
• Nix Package Manager — Nix details and channel setup
• Migrating from Traditional Linux — shell workflow changes
• What's Included — complete software stack
• System Updates — how updates affect your shell config