failed fops attempt

kernel_module/test/ioctl.c

@@ -0,0 +1,33 @@
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+int main(int argc, char **argv)
+{
+	int fd, ret;
+
+	if (argc < 4) {
+		puts("Usage: ./prog <ioctl-file> <cmd> <arg>");
+		return EXIT_FAILURE;
+	}
+	fd = open(argv[1], O_RDONLY);
+	if (fd == -1) {
+		perror("open");
+		return EXIT_FAILURE;
+	}
+	ret = ioctl(fd, strtoul(argv[2], NULL, 10), argv[3]);
+	if (ret == -1) {
+		perror("ioctl");
+		return EXIT_FAILURE;
+	}
+	printf("ret = %d\n", ret);
+	printf("errno = %d\n", errno);
+	close(fd);
+	return EXIT_SUCCESS;
+}