Linux Key Handler

[kanjoe24]

Overview

This application enables generating and emitting virtual input events to the Linux input subsystem via the uinput interface. It uses a user-specified profile YAML file to configure key-event mappings of event type, key code, and value via command-line arguments.

Features:

• Emit Input Events: Generate and send input events programmatically.
• Profile Support: Leverage a YAML file for defining key mappings and event types.
• Manual Input: Specify event type, code, and value via command-line arguments.
• UInput Integration: Use Linux’s /dev/uinput to create and manage virtual devices.

Prerequisites

• Linux system with uinput module enabled.
• Necessary permissions to write to /dev/uinput.
• A valid profile YAML file.

Command-Line Usage

Basic Syntax

./ut_core_key_input -p input-event-codes-5.15.yaml -c KEY_SPACE -t EV_KEY -v 1

Options:

• -p <profile_file> : Path to the profile YAML file defining event types and key mappings. Required.
• -t <event_type> : Type of the event (e.g., EV_KEY). Required.
• -c <event_code> : Event code to emit (e.g., KEY_A). Required.
• -v : Event value to emit: 1,0. Required.

How It Works

1. Profile Loading:
   Reads the profile YAML file using the ut_kvp library.
   Extracts event type and key mappings from yaml file using KVP.
2. UInput Setup:
   Opens /dev/uinput with write permissions.
   Configures the virtual device with UI_DEV_SETUP and UI_DEV_CREATE.
3. Event Emission:
   Uses the emit function to send key events to the virtual device.
   Automatically includes SYN_REPORT to signal event completion.
4. Device Teardown:
   Cleans up kvp resources and destroys the virtual input device with UI_DEV_DESTROY.

[Ulrond]

you should remove -> `./<application_name> and make it ut_core_key_input

it's not going to - validate the file
-> Configures the virtual device with UI_DEV_SETUP and UI_DEV_CREATE. ?? not seen that in teh ode
-> whys it talking about virtual device? Uses the emit function to send key events to the virtual device.

-> does it ? -> Automatically includes SYN_REPORT to signal event completion.
-> Cleans up kvp resources and destroys the virtual input device with UI_DEV_DESTROY.??

remove

Limitations
Requires the uinput kernel module to be loaded.
Assumes the YAML profile file is correctly formatted and contains valid key mappings.

[kanjoe24]

We do use UI_DEV_SETUP, UI_DEV_CREATE and UI_DEV_DESTROY .

ut-core/keyhandler/keyhandler.c

Line 184 in a55f2c0

ioctl(fd, UI_DEV_SETUP, &usetup);

yes, we are sending th SYN_REPORT after every emit :

ut-core/keyhandler/keyhandler.c

Line 53 in a55f2c0

ie.code = SYN_REPORT;