#include<stdio.h>
#include<fcntl.h>
#include<unistd.h>
#include<string.h>

#include<linux/ioctl.h>

#define HJ_MAGICNUM 254
#define HJ_READ _IOR(HJ_MAGICNUM,0,char*)
#define HJ_WRITE _IOR(HJ_MAGICNUM,1,char*)

int main(int argc, char **argv)
{
	int fd;
	char data[256];

	/* Device Open */
	if((fd=open("/dev/hj_ioctl",O_RDWR))<0){
		printf(" Cannot Open the hj_ioctl device file \n");
		return -1;
	}
	else printf("hj_ioctl device driver open OK\n");

	do{
		/* Data Write */
		printf("INPUT DATA('Q':Quit) : ");
		fgets(data, 256, stdin);
		data[strlen(data)-1]='\0';
		ioctl(fd, HJ_WRITE, data);	/* Write Operation */
		printf("hj_ioctl : Write Data \"%s\"(%d)\n", data, strlen(data));

		/* Data Read */
		ioctl(fd, HJ_READ, data);	/* Read Operation */
		printf("hj_ioctl : Read Data \"%s\"\n", data);
	}while(strcmp(data, "Q"));

	/* Device Close */
	close(fd);
	printf("hj_ioctl device driver close OK\n");
	
	return 0;
}