keybdevents.go

// sends fake keyboard events to uinput this example print 'a' to the terminal 

package main

// #cgo CFLAGS: -g -Wall
// #include <linux/uinput.h>
import "C"
import (
	"encoding/binary"
	"io"
	"log"
	"os"
	"syscall"
	"time"
)

type uinput_user_dev C.struct_uinput_user_dev
type timeval C.struct_timeval
type input_event C.struct_input_event

func Press(f io.Writer, k int) error {

	ev := &input_event{
		_type: 1,
		code:  C.__u16(k),
		value: 1,
	}

	err := binary.Write(f, binary.LittleEndian, ev)

	if err != nil {
		log.Fatal(err)
	}

	return nil
}

func Release(f io.Writer, k int) error {

	ev := &input_event{
		_type: 1,
		code:  C.__u16(k),
		value: 0,
	}

	err := binary.Write(f, binary.LittleEndian, ev)

	if err != nil {
		log.Fatal(err)
	}

	return nil
}

func Sync(f io.Writer) error {

	ev := &input_event{
		_type: 0,
		code:  0,
		value: 0,
	}

	err := binary.Write(f, binary.LittleEndian, ev)

	if err != nil {
		log.Fatal(err)
	}

	return nil
}

func WriteStringToCCharArray(carr []C.char, s string) []C.char {

	cb := carr

	for i, c := range s {
		cb[i] = C.char(c)
	}

	return cb
}

func main() {

	f, err := os.OpenFile("/dev/uinput", os.O_WRONLY|syscall.O_NONBLOCK, os.ModeDevice)

	defer f.Close()

	if err != nil {
		log.Fatal(err)
	}

	_, _, errCall := syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), C.UI_SET_EVBIT, uintptr(C.EV_KEY))

	if errCall != 0 {
		log.Fatal(errCall)
	}

	_, _, errCall = syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), C.UI_SET_KEYBIT, uintptr(C.KEY_A))

	if errCall != 0 {
		log.Fatal(errCall)
	}

	uidev := &uinput_user_dev{}
	uidev.id.bustype = C.BUS_USB
	uidev.id.vendor = 0x1
	uidev.id.product = 0x1
	uidev.id.version = 0x1
	uidev.name = [80]C.char(WriteStringToCCharArray(uidev.name[:], "Test"))

	err = binary.Write(f, binary.LittleEndian, uidev)

	if err != nil {
		log.Fatal(err)
	}

	_, _, errCall = syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), C.UI_DEV_CREATE, 0)

	if errCall != 0 {
		log.Fatal(errCall)
	}

	time.Sleep(time.Second * 1)

	Press(f, C.KEY_A)
	Sync(f)
	Release(f, C.KEY_A)
	Sync(f)

	time.Sleep(time.Second * 1)

	_, _, errCall = syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), C.UI_DEV_DESTROY, 0)

	if errCall != 0 {
		log.Fatal(errCall)
	}
}