Send keys to a specific stdin about keybd_event

[s77rt]

I have found a solution for that, but it have nothing to do with the windows api "keybd_event".
So i'm keeping the code here for future ref, hope it helps someone,
also i'm closing this issue for now.

Code: (Windows Only)

func PostKey(pid int, key uint8) (uintptr, error) {
	if runtime.GOOS == "windows" {
		var user32 = syscall.NewLazyDLL("user32.dll")

		EnumWindows := func (enumFunc uintptr, lparam uintptr) {
			user32.NewProc("EnumWindows").Call(uintptr(enumFunc), uintptr(lparam))
		}

		var hwnd uintptr
		cb := syscall.NewCallback(func(h uintptr , prm uintptr) uintptr {
			var itr_pid uint32
			itr_pid = 0x0001
			user32.NewProc("GetWindowThreadProcessId").Call(uintptr(h), uintptr(unsafe.Pointer(&itr_pid)))
			if int(itr_pid) == pid {
				hwnd = h
				user32.NewProc("PostMessageW").Call(h, 0x0100, uintptr(key), 0)
				//return 0 // stop enumeration (commented to make sure all windows created by our process get's the message)
			}
			return 1 // continue enumeration
		})
		EnumWindows(cb, 0)
		if hwnd == 0 {
			return 0, fmt.Errorf("No window with pid %d found", pid)
		}
		return hwnd, nil
	}
	return 0, fmt.Errorf("unsupported os")
}

Example:

PostKey(7777, 0x53) will send the key 'S' to all the windows that are created by the process which it's id is 7777
list of keys

Notes:

If you are using a pid = cmd.Process.Pid (os/exec)
your binary should be built passing the "-H=windowsgui" flag

[micmonay]

The library simulates a keyboard and it has the same output with the hardware keyboard. If you have a solution to set multiple keyboards on various output, it is probably possible. But I don't know if that exists.

(The library does not specify the output)