regmsg

regmsg is a command-line utility and daemon for managing screen resolution and display settings on Linux systems, with support for both Wayland compositors and KMS/DRM backends.

Features

• Display Management: Manage screen resolution, orientation, refresh rate, and output settings
• Dual Backend Support: Works with both KMS/DRM and Wayland (Sway) backends
• Daemon Architecture: Client-server architecture with persistent daemon for efficient display management
• Advanced Tracing: Comprehensive logging with dual output to file and console, supporting environment-based filtering
• Lightweight and Optimized: Designed for performance with async I/O
• Scripting Support: Designed for automation and integration in tiling window manager environments

Architecture

The system consists of two main components:

• regmsg: Command-line client that communicates with the daemon
• regmsgd: Background daemon that manages display settings using ZeroMQ for IPC

Usage

Client (regmsg)

regmsg [OPTIONS] [COMMAND]

Daemon (regmsgd)

regmsgd

For a full list of options and commands, use:

regmsg --help

Common commands include:

• listModes: List available display modes
• currentMode: Get current display mode
• setMode <mode>: Set display mode (e.g., "1920x1080@60")
• setRotation <rotation>: Set display rotation (0, 90, 180, 270)
• getScreenshot: Take a screenshot
• mapTouchScreen: Map touchscreen to display

Building

To build regmsg, you need to have the Rust toolchain installed. You can install it using rustup.

git clone https://github.com/REG-Linux/regmsg.git
cd regmsg
cargo build --release

The compiled binaries will be located in the target/release directory.

Logging and Tracing

The daemon implements a robust tracing mechanism with:

• Dual Output: Logs are written both to console/stdout for debugging and to a file (/var/log/regmsg.log by default) for persistent record keeping
• Environment Filtering: Supports RUST_LOG environment variable for controlling log levels (e.g., RUST_LOG=debug)
• Non-blocking I/O: Uses non-blocking writers to prevent logging from affecting system performance
• No Automatic Rotation: Single log file approach to allow system-level log management tools like logrotate
• ANSI Support: Colored output to console and plain text to file for optimal readability

Requirements

• Rust (edition 2024 or later)
• A Wayland compositor (e.g., Sway) or DRM support for KMS/DRM backend
• ZeroMQ library for IPC communication

License

This project is licensed under the MIT License.