How to use the command 'hidd' (with examples)

The hidd command is a daemon used for Human Interface Device (HID) support in macOS. The HID library userland daemon is responsible for managing input devices such as keyboards, mice, and trackpads. This command is integral to ensuring that user inputs via these devices are processed correctly by the operating system. Although hidd is generally not invoked manually, understanding its purpose and basic invocation can be useful for certain system troubleshooting or configuration tasks.

Use case 1: Start the daemon

Code:

hidd

Motivation:
The primary motivation for starting the hidd daemon is to initialize or restart the human interface device event handling services on your macOS system. This can be particularly useful if you find that your input devices are not responding correctly or if you need to troubleshoot issues related to keyboard, mouse, or trackpad functionality. While users typically do not manually start hidd, knowing how to do so can be a part of diagnosing and resolving such issues.

Explanation:
The command simply consists of calling hidd without any additional arguments or options. This is because hidd operates as a background daemon, and its primary function is to continuously run, monitoring and managing input devices. In a standard setup, hidd starts automatically at system boot without direct user intervention. By manually starting it, you are effectively reinitializing the service, which can be necessary if the daemon was inadvertently terminated or if its service became unresponsive.

Example Output:
Invoking hidd directly would not typically provide an output to the terminal. However, running it successfully in the shell will ensure that the daemon is operational and that input devices should begin to function normally if they were previously experiencing issues.

Conclusion:

The hidd daemon plays a crucial role in the macOS environment, managing input devices efficiently and transparently to the user. Although hidd is not conventionally operated manually, understanding its purpose and how to start it can be invaluable in specific troubleshooting contexts. The command itself is minimal, focusing solely on initializing the background service that handles input events from HID devices.