6_1

#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdint.h>
#include <stdio.h>

struct Item {
  int value;
  uint32_t next_pointer;
};

int main(int args, char* argv[]) {
    if (args == 1) return 0;
    int input_file = open(argv[1], O_RDONLY);
    struct Item curr_item;
    curr_item.value = -1;
    curr_item.next_pointer = -1;
    if (read(input_file, &(curr_item.value), sizeof(curr_item.value)) <= 0) {
        return 0;
    }
    read(input_file, &(curr_item.next_pointer), sizeof(curr_item.next_pointer));
    while (curr_item.next_pointer > 0) {
        printf("%d ", curr_item.value);
        lseek(input_file, curr_item.next_pointer, SEEK_SET);
        read (input_file, &(curr_item.value),        sizeof(curr_item.value));
        read (input_file, &(curr_item.next_pointer), sizeof(curr_item.next_pointer));
    }
    printf("%d", curr_item.value);
    close(input_file);
    return 0;
}