Você pode usar uinput ( linux/uinput.h ). Funciona tanto em X quanto em Wayland.
A página de documentação acima tem um exemplo que inclui a criação de um dispositivo virtual que se comporta como um mouse:
#include <linux/uinput.h>
void emit(int fd, int type, int code, int val)
{
struct input_event ie;
ie.type = type;
ie.code = code;
ie.value = val;
/* timestamp values below are ignored */
ie.time.tv_sec = 0;
ie.time.tv_usec = 0;
write(fd, &ie, sizeof(ie));
}
int main(void)
{
struct uinput_setup usetup;
int i = 50;
int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
/* enable mouse button left and relative events */
ioctl(fd, UI_SET_EVBIT, EV_KEY);
ioctl(fd, UI_SET_KEYBIT, BTN_LEFT);
ioctl(fd, UI_SET_EVBIT, EV_REL);
ioctl(fd, UI_SET_RELBIT, REL_X);
ioctl(fd, UI_SET_RELBIT, REL_Y);
memset(&usetup, 0, sizeof(usetup));
usetup.id.bustype = BUS_USB;
usetup.id.vendor = 0x1234; /* sample vendor */
usetup.id.product = 0x5678; /* sample product */
strcpy(usetup.name, "Example device");
ioctl(fd, UI_DEV_SETUP, &usetup);
ioctl(fd, UI_DEV_CREATE);
/*
* On UI_DEV_CREATE the kernel will create the device node for this
* device. We are inserting a pause here so that userspace has time
* to detect, initialize the new device, and can start listening to
* the event, otherwise it will not notice the event we are about
* to send. This pause is only needed in our example code!
*/
sleep(1);
/* Move the mouse diagonally, 5 units per axis */
while (i--) {
emit(fd, EV_REL, REL_X, 5);
emit(fd, EV_REL, REL_Y, 5);
emit(fd, EV_SYN, SYN_REPORT, 0);
usleep(15000);
}
/*
* Give userspace some time to read the events before we destroy the
* device with UI_DEV_DESTOY.
*/
sleep(1);
ioctl(fd, UI_DEV_DESTROY);
close(fd);
return 0;
}