qudev – Qt wrapper around libudev + QML viewer

qudev is a small C++/Qt6 library that wraps libudev (udev) on Linux and provides a QML/QtQuick example viewer for enumerating and monitoring devices.

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Features

• High-level façade: Qudev class for enumeration + monitoring.
• Device representation: QudevDevice as a Qt metatype
  (easy to use in signals/slots, QVariant, QML).
• Filtering (QudevFilters):
  • Exact matches on subsystem, devtype, sysname, devnode, syspath prefixes.
  • Property and sysattr matching / non-matching.
  • Tag and action filters.
• Enumeration (Qudev::enumerate()):
  • Snapshot of all devices matching the current filters.
• Monitoring:
  • Event-based device notifications via the deviceFound(const QudevDevice&) signal.
  • Internally uses QSocketNotifier and libudev monitors.
• Example viewer (udevviewer):
  • Qt Quick / Material UI.
  • Tree view of devices grouped by subsystem.
  • Filter drawer for building QudevFilters.
  • Demonstrates how to use the synchronous library from QML in an asynchronous way via a dedicated QudevService wrapper.

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Requirements

• Qt: Qt 6.5+ (Core, Gui, Qml, Quick)
• libudev (from systemd or eudev), accessible via pkg-config libudev
• CMake: 3.23+
• A C++17-capable compiler

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Building

Command line

git clone https://github.com/GregorSuperSamsa/qudev
cd qudev

# Configure (adjust CMAKE_PREFIX_PATH to your Qt if needed)
cmake -S . -B build \
      -DQUDEV_BUILD_EXAMPLES=ON \
      -DQUDEV_BUILD_TESTS=OFF \
      -DQUDEV_BUILD_DOCS=ON

# Build library + example
cmake --build build

This will produce:

• build/src/libqudev.a (or .so)
• build/examples/udevviewer/udevviewer – the example app

Qt Creator

• Open CMakeLists.txt as a project.
• In the CMake configuration step, make sure:
  • QUDEV_BUILD_EXAMPLES is ON if you want the viewer.
  • QUDEV_BUILD_DOCS is ON if you want the Doxygen target.
• Select the desired configuration (Debug/Release) and build normally.

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Running the example viewer

After building:

cd build
./examples/udevviewer/udevviewer

You should see a dark Material-themed window:

• Scan devices enumerates devices matching the current filters.
• Start monitoring / Stop monitoring toggles live monitoring of new events.
• Filters opens a side drawer where you can edit QudevFilters from QML.
• Filter devices dynamically... enables realtime filtering of the found devices by any user input.
• The device tree groups devices by subsystem and exposes properties, sysfs attributes, tags, and other metadata.

Note: libudev typically requires access to /sys and /dev, so the example is intended to run on a Linux system with udev.

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Documentation (Doxygen)

Doxygen configuration is provided via Doxyfile. To generate HTML docs:

# From the build directory configured with QUDEV_BUILD_DOCS=ON
cmake --build build --target doc

This will generate HTML documentation in:

docs/html/index.html

Open that file in a browser to explore the API (public headers under include/ are the interesting bits).

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License

This project is licensed under the MIT License.
See the LICENSE file for full license text.