zmenu

A cross-platform dmenu-like application launcher built with Zig and SDL3.

Features

• Fast and lightweight menu selection interface
• Fuzzy matching - Type letters and they can match anywhere (e.g., "abc" matches "a_b_c")
• Case-insensitive filtering - Search without worrying about caps (ASCII only)
• UTF-8 safe - Handles multi-byte characters correctly in input and items
• Multi-line display - See up to 10 items at once with scrolling
• Keyboard-driven navigation with vim-style keybindings
• Cross-platform - Runs on Linux, Windows, and macOS without code changes
• Zero configuration - Works out of the box with sensible defaults

Usage

zmenu reads items from stdin and displays them in a menu:

# Simple example
echo -e "Apple\nBanana\nCherry\nDate\nEldberry" | zmenu

# From a file
cat items.txt | zmenu

# Use with find
find . -type f | zmenu

The selected item is written to stdout, making it easy to use in scripts:

selected=$(find ~/projects -maxdepth 1 -type d | zmenu)
cd "$selected"

Keyboard Controls

Navigation:

• ↑ / k - Move selection up
• ↓ / j - Move selection down
• Tab - Move to next item
• Shift+Tab - Move to previous item
• Page Up - Jump up one page (10 items)
• Page Down - Jump down one page (10 items)
• Home - Jump to first item
• End - Jump to last item

Input:

• Type any text - Fuzzy filter items (case-insensitive, UTF-8 safe)
• Backspace - Delete last character (UTF-8 aware)
• Ctrl+U - Clear entire input
• Ctrl+W - Delete last word

Actions:

• Enter - Select current item and output to stdout
• Escape / Ctrl+C - Cancel without selection

Display

• Top left: Input prompt with your query
• Top right: Filtered count / Total items
• Bottom right (if needed): Scroll indicator showing visible range
• Selected item has > prefix and highlighted color

Themes

zmenu supports multiple color themes via the ZMENU_THEME environment variable:

# Use a specific theme (note: env var must be set for zmenu, not the input command)
echo -e "Apple\nBanana\nCherry" | ZMENU_THEME=dracula zmenu

# Works with any command
find . -type f | ZMENU_THEME=nord zmenu

# Or export first, then use normally
export ZMENU_THEME=gruvbox
seq 1 100 | zmenu

# Set as default in your shell config (~/.bashrc, ~/.zshrc, etc.)
export ZMENU_THEME=gruvbox

Available Themes

Catppuccin Family (pastel themes):

• mocha (default) - Dark pastel with purple-gray background
• latte - Light pastel with lavender background
• frappe - Medium-dark pastel
• macchiato - Dark-medium pastel

Classic Themes:

• dracula - Popular dark theme with vibrant pink/cyan accents
• gruvbox - Retro warm dark theme with earthy tones
• nord - Cool arctic-inspired theme with blue accents
• solarized - Low-contrast dark theme

If ZMENU_THEME is not set or contains an invalid name, zmenu defaults to mocha.

Theme names are case-insensitive (NORD, nord, and NoRd all work).

Development

• mise for version management
• No SDL3 system libraries required! - zig-sdl3 bundles everything

Setup

1. Install mise (if not already installed):

curl https://mise.run | sh

1. Install Zig via mise:

mise install

1. Build the project:

mise run build

Available mise Tasks

• mise run build - Build the project
• mise run run - Run the application
• mise run test - Run tests
• mise run clean - Clean build artifacts
• mise run check - Check code without building

Project Structure

zmenu/
├── .mise.toml          # Mise configuration and tasks
├── build.zig           # Build configuration
├── build.zig.zon       # Dependencies (zig-sdl3)
├── src/
│   ├── main.zig        # Main application (~740 lines)
│   └── theme.zig       # Theme definitions (8 color themes)
└── README.md

Implementation Details

Fuzzy Matching Algorithm

The fuzzy matcher allows characters to appear in order but not necessarily consecutively:

Query: "abc"
Matches: "AaBbCc", "a_long_b_string_c", "AbsolutelyBigCat"
No Match: "cba", "acb"

Important: Case-insensitive matching only works for ASCII characters (a-z, A-Z). UTF-8 characters like é, ü, 日 are matched byte-for-byte:

• ✅ "Café" matches "caf" (ASCII part is case-insensitive)
• ❌ "café" does NOT match "cafe" (é ≠ e)
• ✅ "日本語" matches "日本" (exact UTF-8 bytes)

This design choice ensures UTF-8 safety without complex Unicode normalization.

Design Philosophy

This project follows a pragmatic approach:

• Simple, maintainable code - Single ~500-line file, easy to understand
• Minimal dependencies - Just zig-sdl3 (which bundles SDL3)
• Clear separation of concerns - Init, event handling, rendering, filtering
• Performance-conscious but readable - Optimized where it matters, clear elsewhere
• Helper methods - Navigation, text editing extracted to focused functions

Testing

The project includes automated tests covering critical functionality:

mise run test  # Run all tests

Test Coverage:

• Fuzzy matching (basic, case-insensitive, UTF-8 handling)
• UTF-8 boundary detection for safe truncation
• UTF-8 aware character deletion (backspace, word deletion)
• Color comparison
• Configuration validation

All tests use Zig's built-in testing framework and run on every build.

Cross-Platform

Supported Platforms: Linux, macOS, Windows

Building for different platforms:

# Native build
mise run build

# Cross-compile to Windows
zig build -Dtarget=x86_64-windows

# Cross-compile to macOS
zig build -Dtarget=x86_64-macos

# Cross-compile to Linux
zig build -Dtarget=x86_64-linux

Known limitations

• No configuration file support yet
• No history/frecency tracking
• Window size is fixed (800x300)

Future Enhancements

Planned:
Configuration file support (~/.config/zmenu/config.toml)
History tracking with frecency scoring
Multi-column layout option
Preview pane for file paths
Custom keybinding support

Maybe:
Plugin system for custom filters
Custom theme support (user-defined colors)
Desktop file integration (.desktop files)
Icon support

Contributing

This is a learning project exploring Zig + SDL3.

Discussions, issues and PRs are welcomed!

License

This project is open source. Use it however you'd like.