readbin.c

#include <stdio.h>

typedef struct _user_info {
	int id;
	char name[20];
} user_info;

int main()
{
	user_info user;
	FILE *fp;

	user.id = 0;
	
	fp = fopen("data", "rb");
	fread (&user, sizeof(user_info), 1, fp);
	fclose (fp);

	printf("id: %d, name: %s\n", user.id, user.name);

	return 1;
}