linux-kernel-module-cheat/kernel_module/user/anonymous_inode.c

#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h> /* sleep */

#include "../anonymous_inode.h"

int main(int argc, char **argv)
{
	char buf[1024];
	int fd_ioctl, fd_ioctl_anon, ret;

	if (argc < 2) {
		puts("Usage: ./prog <ioctl-file>");
		return EXIT_FAILURE;
	}
	fd_ioctl = open(argv[1], O_RDONLY);
	if (fd_ioctl == -1) {
		perror("open");
		return EXIT_FAILURE;
	}
	ret = ioctl(fd_ioctl, LKMC_ANONYMOUS_INODE_GET_FD, &fd_ioctl_anon);
	if (ret == -1) {
		perror("ioctl");
		return EXIT_FAILURE;
	}
	ret = read(fd_ioctl_anon, buf, sizeof(buf));
	printf("%.*s\n", ret, buf);
	sleep(1);
	ret = read(fd_ioctl_anon, buf, sizeof(buf));
	printf("%.*s\n", ret, buf);
	close(fd_ioctl_anon);
	close(fd_ioctl);
	return EXIT_SUCCESS;
}