gtk-ahfail/readme.md

Ah ah ah, you didn't say the magic word

This gtklock module listens for failed unlock attempts and recreates Dennis Nedry’s “ah ah ah” lockout scene from Jurassic Park.

• Animation: Spawns a looping "Nedry" sprite at a random location on the screen.
• Audio: Plays the "ah ah ah, you didn't say the magic word" clip.
• Safety: Sprites avoid overlapping a configurable "deadzone" (e.g., your login box).
• Performance: Uses pre-warmed audio players for low latency and scaled images to fit any screen.

Requirements

• Build: Meson, Ninja, Rust (Cargo), GTK+3 development headers.
• Runtime: gtklock, gstreamer, gst-plugins-base, gst-plugins-good (for audio playback).

Build & Install

1. Install Dependencies (Arch Linux example):

   sudo pacman -S meson ninja rust gtk3 gstreamer gst-plugins-base gst-plugins-good gst-libav
   

2. Build:

   meson setup builddir
   meson compile -C builddir
   

3. Install:

   sudo meson install -C builddir
   

Usage

Run gtklock with the module path:

gtklock -m /usr/lib/gtklock/ahfail-module.so

Arguments

• --deadzone=X,Y,W,H: Defines a rectangle where sprites will not spawn (e.g., to keep your password field visible).

  gtklock -m ahfail-module.so -- --deadzone=860,440,200,200
  

  (Note the -- separator before module arguments)

• --audio-uri=URI: Override the default audio clip.

  gtklock -m ahfail-module.so -- --audio-uri=file:///home/user/custom.mp3
  

macOS (build from source)

Prerequisites

brew install gtk+3 gstreamer gst-plugins-base gst-plugins-good meson ninja rust

Build

meson setup builddir
meson compile -C builddir

Produces:

• builddir/ahfail-module.so — gtklock module (Wayland/Linux only)
• builddir/libahfail_pam.so — PAM module (macOS + X11 Linux)
• builddir/ahfail-display — display binary (spawned by PAM module)

Install

sudo mkdir -p /usr/local/lib/ahfail
sudo cp builddir/libahfail_pam.so /usr/local/lib/ahfail/
sudo cp builddir/ahfail-display /usr/local/lib/ahfail/

Configure PAM (macOS)

Add to /etc/pam.d/screensaver (requires sudo):

auth optional /usr/local/lib/ahfail/libahfail_pam.so

Place it after the existing auth line(s) so it observes the real auth result.

Configure PAM (Linux/X11)

Add to /etc/pam.d/gtklock (or i3lock, xscreensaver, etc.):

auth optional ahfail-pam.so

Development

• Run Tests: cargo test
• Benchmarks: cargo test --test benchmarks -- --nocapture
• Linting: cargo clippy

Customization

To change the default sprite or audio:

1. Replace files in assets/.
2. Update assets/ahfail.gresource.xml.
3. Rebuild with Meson.