InstallScriptTemplate

A starting point for interactive Bash installer scripts in the Violet-Noir style: a full-screen wizard that fits 80×24, runs every system change through one dry-run-aware helper, and shows live command output in a framed install screen.

install-script-template.sh works as-is. Every action in it is a harmless placeholder (echo output and sudo -n true), so you can run it to see every screen before building anything.

The wizard

Welcome: the system, the user and the desktop session, plus what the installer can set up.
Selection pages: package groups on page 1, then two pages of actions.
Review selections: every item with its status (installed, install, apply, skip), in two columns.
Review the plan: a summary of what will run. Problems that would make the run fail are shown as blockers, and Enter stays disabled until they are fixed.
Authenticate: the sudo password goes to sudo -S -v through a pipe, never argv, the environment or the log. A keepalive refreshes it during the run.
Install steps: each step runs with its output in a frame. A failure stops for a choice: fatal steps end the run, the others offer Continue or Stop. Ctrl+C stops after the current step, so a package manager is never interrupted mid-transaction.
Completion: one line per step with its status and duration, any reboot or log-out notes, and Ctrl+D for the full log.

Keys: ↑↓ or j/k move, ←→ or h/l switch columns, Space toggles, G toggles a group, A/N select all or none, Enter goes on, B or Backspace goes back, Esc quits.

Try it

./install-script-template.sh            # the full wizard
./install-script-template.sh -n         # dry run: commands are shown, not run
./install-script-template.sh -pt        # preselect groups, open at the review screen
DEMO_FAIL_STEP=3 ./install-script-template.sh   # see how a failed step looks
DEMO_BLOCK=1 ./install-script-template.sh       # see a plan blocker
./install-script-template.sh --help

Making a new installer

Copy the template, then edit only the four sections marked CUSTOMIZE:

Section	What goes there
1. Identity and flags	`APP_NAME`, `SCRIPT_SLUG`, `usage`, one short flag per selection group, `apply_preselection`
2. Items, groups and steps	the item arrays, `GROUP_` tables, page titles, `PHASE_` step tables and `phase_enabled`
3. Checks	`prerequisite_problem`, `package_installed`, `collect_plan_blockers`, `plan_group_notes`, `after_step_hook`
4. Step functions	one function per install step

Everything else (layout, keys, the output frame, dry run, the sudo keepalive) is engine code that should not need changes. Remove the demo helpers (DEMO_INSTALLED, demo_output, demo_fail_check) from real scripts.

Rules for step functions:

Send every command that changes the system through run or as_root (or a wrapper built on them, such as pacman_install). In a dry run they print → would run: … instead. Read-only checks always run for real.
Print progress with info, success, warn and error; the frame colors lines by their prefix.
Steps run with no keyboard input (stdin is /dev/null), so anything that would prompt must fail instead. Check every exit status and return nonzero on failure.
Back up a config file before replacing it.

Checks before release

bash -n script.sh
shellcheck -S warning -e SC2034,SC2178 script.sh   # those two are nameref false positives
script.sh --dry-run

Then look at every screen at 80×24 and 100×24, and with LC_ALL=C for the ASCII fallback, and do a real run in a VM snapshot.

Requirements

Bash 4.4 or newer, a terminal of at least 80×24, and sudo. Run it as your normal user; it refuses to run as root.

Scripts built on it

Arch-GKuba post-install.sh: the reference implementation of the engine.
dotfiles setup-dotfiles.sh: shell tools, the bare dotfiles repo, Zsh plugins and Fastfetch preferences on pacman and apt systems.

License

MIT; see LICENSE.

From the README