uinput test script for 200+ input devices

uinput_test.c

#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <linux/input.h>
#include <linux/uinput.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>

static const char *uinput_path = "/dev/uinput";
static const char *uinput_name = "Test Device";

static int uinput_create(void)
{
	int ret, fd;
	struct uinput_user_dev udev;

	fd = open(uinput_path, O_RDWR | O_CLOEXEC | O_NONBLOCK);
	if (fd < 0) {
		fprintf(stderr, "cannot open uinput (%d): %m\n", errno);
		return -errno;
	}

	memset(&udev, 0, sizeof(udev));
	strncpy(udev.name, uinput_name, UINPUT_MAX_NAME_SIZE);
	udev.id.bustype = BUS_VIRTUAL;
	udev.id.vendor = 0x0306;
	udev.id.product = 0x0101;
	udev.id.version = 0;

	ret = write(fd, &udev, sizeof(udev));
	if (ret != sizeof(udev)) {
		fprintf(stderr, "cannot init uinput (%d): %m\n", errno);
		close(fd);
		return -errno;
	}

	ret = ioctl(fd, UI_SET_EVBIT, EV_KEY);
	if (ret) {
		fprintf(stderr, "cannot set EV_KEY (%d): %m\n", errno);
		close(fd);
		return -errno;
	}

	ret = ioctl(fd, UI_SET_KEYBIT, KEY_A);
	if (ret) {
		fprintf(stderr, "cannot set KEY_A (%d): %m\n", errno);
		close(fd);
		return -errno;
	}

	ret = ioctl(fd, UI_DEV_CREATE);
	if (ret) {
		fprintf(stderr, "cannot create uinput (%d): %m\n", errno);
		close(fd);
		return -errno;
	}

	return fd;
}

static void uinput_destroy(int fd)
{
	ioctl(fd, UI_DEV_DESTROY);
	close(fd);
}

int main(int argc, char **argv)
{
	int i, max, slp, step, *fds;

	if (argc < 2)
		max = 10;
	else
		max = atoi(argv[1]);

	if (max <= 0) {
		fprintf(stderr, "'max' argument smaller than 1: %d\n", max);
		return EINVAL;
	}

	if (argc < 3)
		slp = 30;
	else
		slp = atoi(argv[2]);

	if (slp <= 0) {
		fprintf(stderr, "'sleep' argument smaller than 1: %d\n", slp);
		return EINVAL;
	}

	fprintf(stderr, "creating %d uinput devices\n", max);

	fds = malloc(sizeof(int) * max);
	if (!fds) {
		fprintf(stderr, "cannot allocate memory for FD array\n");
		return ENOMEM;
	}

	for (i = 0; i < max; ++i) {
		fds[i] = uinput_create();
		fprintf(stderr, "creating uinput device #%d: %s\n",
			i, (fds[i] >= 0) ? "success" : "failed");
	}

	fprintf(stderr, "sleeping for %d seconds\n", slp);
	step = slp / 5;
	for (i = 0; i < step; ++i) {
		fprintf(stderr, "%d seconds to go\n",
			slp - i * 5);
		sleep(5);
	}
	step = slp % 5;
	if (step) {
		fprintf(stderr, "%d seconds to go\n", step);
		sleep(step);
	}

	fprintf(stderr, "destroying uinput devices\n");
	for (i = 0; i < max; ++i) {
		if (fds[i] >= 0)
			uinput_destroy(fds[i]);
	}

	fprintf(stderr, "exiting\n");
	return 0;
}