Zapis vuv fail

void psn(lst *head, FILE *fp)
{
    if (head == NULL)
    {
        printf("The list is empty");
        return;
    }

    int err = 0;
    while (head != NULL)
    {
        if (err = fprintf(fp, "%s\n", head->data.name) != 1)
            printf("Greshka pri zapis\n");

        if (err = fprintf(fp, "%d\n", head->data.num) != 1)
            printf("Greshka pri zapis\n");

        if (err = fprintf(fp, "%f\n", head->data.cht) != 1)
            printf("Greshka pri zapis\n");

        head = head->next;
    }

    if (fp)
        fclose(fp);
}