Uinput
This package provides pure go wrapper functions for the LINUX uinput device, which allows to create virtual input devices
in userspace. At the moment this package offers a virtual keyboard implementation as well as a virtual mouse device and
a touch pad device.
The keyboard can be used to either send single key presses or hold down a specified key and release it later
(useful for building game controllers). The mouse device issues relative positional change events to the x and y axis
of the mouse pointer and may also fire click events (left and right click). For implementing things like region selects
via a virtual mouse pointer, press and release functions for the mouse device are also included.
The touch pad, on the other hand can be used to move the mouse cursor to the specified position on the screen and to
issue left and right clicks. Note that you'll need to specify the region size of your screen first though (happens during
device creation).
Please note that you will need to make sure to have the necessary rights to write to uinput. You can either chmod your
uinput device, or add a rule in /etc/udev/rules.d to allow your user's group or a dedicated group to write to the device.
You may use the following two commands to add the necessary rights for you current user to a file called 99-$USER.rules
(where $USER is your current user's name):
echo KERNEL==\"uinput\", GROUP=\"$USER\", MODE:=\"0660\" | sudo tee /etc/udev/rules.d/99-$USER.rules
sudo udevadm trigger
Installation
Simply check out the repository and use the commands
go build && go install
The package will then be installed to your local respository, along with the package documentation.
The documentation contains more details on the usage of this package.
Alternatively, if you'd like to use a specific version/tag of this library, you may use the gopkg.in service.
To get v.1.x.x (latest stable v1), simply enter this on your command line:
go get gopkg.in/bendahl/uinput.v1
To import this version in your code use:
import "gopkg.in/bendahl/uinput.v1"
You may then refer to it as "uinput" in your code. For further details see: https://gopkg.in/bendahl/uinput.v1
Thanks to gopkg.in for offering this great service!
Usage
The following section explains some common ways to use this lib.
Using the virtual keyboard device:
package main
import "github.com/bendahl/uinput"
func main() {
keyboard, err := uinput.CreateKeyboard("/dev/uinput", []byte("testkeyboard"))
if err != nil {
return
}
defer keyboard.Close()
keyboard.KeyPress(uinput.KeyA)
keyboard.KeyDown(uinput.KeyLeftshift)
keyboard.KeyPress(uinput.KeyA)
keyboard.KeyUp(uinput.KeyLeftshift)
for i := 0; i < 5; i++ {
keyboard.KeyPress(uinput.Key0)
}
}
Using the virtual mouse device:
package main
import "github.com/bendahl/uinput"
func main() {
mouse, err := uinput.CreateMouse("/dev/uinput", []byte("testmouse"))
if err != nil {
return
}
defer mouse.Close()
mouse.MoveUp(10)
mouse.MoveRight(10)
mouse.MoveDown(10)
mouse.MoveLeft(10)
mouse.LeftClick()
mouse.RightClick()
mouse.LeftPress()
mouse.MoveDown(100)
mouse.LeftRelease()
}
Using the virtual touch pad device:
package main
import "github.com/bendahl/uinput"
func main() {
touch, err := uinput.CreateTouchPad("/dev/uinput", []byte("testpad"), 0, 800, 0, 600)
if err != nil {
return
}
defer touch.Close()
touch.MoveTo(300, 200)
touch.LeftPress()
touch.MoveTo(400, 400)
touch.LeftRelease()
}
License
The package falls under the MIT license. Please see the "LICENSE" file for details.
Design Decisions
After some consideration the validation logic of the uinput module was adapted. Instead of simply returning and error code
it actually panics. The reasoning behind this is that invalid initialization parameters for the uinput device may be a clue
for a programming error that should never pass silently. Also, faulty initialization values would simply cause the uinput
device not to work. "Effective Go" also suggests to use panics in occasions where a library simply cannot set itself up due
to improper initialization (see: Effective Go).
Current Status
2018-03-31: I am happy to announce that v1.0.0 is finally out! Go ahead and use this library in your own projects! Feedback is always welcome.
TODO
The current API can be considered stable and the overall functionality (as originally envisioned) is complete.
Testing on x86_64 and ARM platforms (specifically the RaspberryPi) has been successful. If you'd like to use this library
on a different platform that supports Linux, feel free to test it and share the results. This would be greatly appreciated.
One thing that I'd still like to improve, however, are the test cases. The basic functionality is covered, but more extensive
testing is something that needs to be worked on.