why doesn't my pointer increase to the next index?

Question

So, if i change buf[t_index] to *buf(got a before & after below), and do buf++ instead of t_index++, i get a segmentation fault, what's the cause of this? my study requires limited function lines, and i have 1 too many =[.

BEFORE:

t_tetrimino     *ft_sort_list(char **buf, int x, int y, int block)
{
    t_tetrimino *curr;
    t_tetrimino *head;
    int         t_index;
    int         index;

    index = 0;
    t_index = 0;
    curr = (t_tetrimino*)malloc(sizeof(t_tetrimino));
    head = curr;
    while (buf[t_index] != NULL)
    {
        if (ft_validator(buf[t_index], 0, 0, 0) == -1)
            return (NULL);
        while (buf[t_index][index])
        {
            if (buf[t_index][index] == '#')
                (curr->x[block] = x) && (curr->y[block] = y) && block++;
            buf[t_index][index] == '\n' && index != 19 ? (y++ && (x = 0)) : x++;
            index++;
        }
        set_tetr_properties(&curr);
        reset_vars(&block, &x, &y, &index);
        t_index++;
    }
    return (head);
}

WHAT I WANT:

t_tetrimino     *ft_sort_list(char **buf, int x, int y, int block)
{
    t_tetrimino *curr;
    t_tetrimino *head;
    int         t_index;
    int         index;

    index = 0;
    t_index = 0;
    curr = (t_tetrimino*)malloc(sizeof(t_tetrimino));
    head = curr;
    while (*buf != NULL)
    {
        if (ft_validator(*buf, 0, 0, 0) == -1)
            return (NULL);
        while (*buf[index])
        {
            if (*buf[index] == '#')
                (curr->x[block] = x) && (curr->y[block] = y) && block++;
            *buf[index] == '\n' && index != 19 ? (y++ && (x = 0)) : x++;
            index++;
        }
        set_tetr_properties(&curr);
        reset_vars(&block, &x, &y, &index);
        buf++;
    }
    return (head);
}

By operator precedence rules, `*buf[index]` means `*(buf[index])` (same as `**(buf + index)`), but what you want is `(*buf)[index]` (same as `*(*buf + index)`). — Ian Abbott, May 24 '19 at 17:40
PSA: [Don't cast the result of `malloc`](https://stackoverflow.com/questions/605845/do-i-cast-the-result-of-malloc). — tadman, May 24 '19 at 18:24
@tadman i know haha thanks, my school requires a certain norm — Dave, May 24 '19 at 18:25
Most schools have little to no clue what they're teaching, so always take their advice with a couple of pounds of salt. Do what you need to do to get through the course and hope you survive! — tadman, May 24 '19 at 18:27

why doesn't my pointer increase to the next index?

0 Answers0