[ANN] lua-evdev: interact with input devices on Linux

[Joseph Wallace <tangent128@...>]

Hello, all;

I'm happy to announce a simple Lua 5.2 module I put together for using
the Linux evdev (EVent DEVice) and uinput (User-mode Input) APIs.

This can be useful for reading data from drawing tablets, game controllers,
as well as emulating keyboards, mice, tablets, and controllers.

The "Device" object is suitable for polling by cqueues if you like that
event loop,
but there are no special dependencies.

You can get it by installing the "evdev" rock,
or find the source and fuller documentation at
https://github.com/Tangent128/lua-evdev/tree/evdev-1.0

Here's hoping somebody else can have fun with it!


Example: Reading events from /dev/input/event* nodes:
---

local evdev = require "evdev"
-- (assuming event0 is the keyboard today)
local keyboard = evdev.Device "/dev/input/event0"
while true do
    local timestamp, eventType, eventCode, value = keyboard:read()
    if eventType == evdev.EV_KEY then
        if eventCode == evdev.KEY_ESC then
            break
        end
        if value == 0 then
            print("Key Released:", eventCode)
        else
            print("Key Pressed:", eventCode)
        end
    end
end


Example: Creating a fake mouse:
---

local e = require "evdev"
local fakeMouse = e.Uinput "/dev/uinput"
-- register supported events
fakeMouse:useEvent(e.EV_KEY)
fakeMouse:useEvent(e.EV_REL)
fakeMouse:useKey(e.BTN_0)
fakeMouse:useKey(e.BTN_1)
fakeMouse:useRelAxis(e.REL_X,-100,100)
fakeMouse:useRelAxis(e.REL_Y,-100,100)
fakeMouse:init()
-- inject a few events; mouse move, button press, button release
fakeMouse:write(e.EV_REL, e.REL_X, -50)
fakeMouse:write(e.EV_REL, e.REL_Y, 0)
fakeMouse:write(e.EV_SYN, e.SYN_REPORT, 0)
fakeMouse:write(e.EV_KEY, e.BTN_0, 1)
fakeMouse:write(e.EV_SYN, e.SYN_REPORT, 0)
fakeMouse:write(e.EV_KEY, e.BTN_0, 0)
fakeMouse:write(e.EV_SYN, e.SYN_REPORT, 0)
-- dispose
fakeMouse:close()


---
"Tangent"
Joseph Wallace