How can i fix an issue with padding in c?

Question

I am trying to make it so that no matter the length of the variable (eg char customer with max length of 16 ) will be aligned with the heading Customer as so:

#   Customer                  Pizza               Price     Time      
---------+---------+---------+---------+---------+---------+---------+---------+
01  Nick                      Hawaiian            $15.99    15
---------+---------+---------+---------+---------+---------+---------+---------+

Note: i am trying to implement this in a way where the variable of name is inputed by the user, thus its length differing.

Below i am getting a segmentation fault and in my code below and do not know why:

void print_header(struct pizzeria *the_pizzeria) {
    printf("#   Customer                  Pizza               Price     Time\n");
    printf("--------------------------------------------------------------------------------\n");

}

void print_order(struct order *the_order, int order_number, bool selected) {
    int space_pizza = (26 - (strlen(the_order->customer)));
    int space_cost = (26 - (strlen(the_order->pizza)));
    int space_time = 5;
    
    if (selected == true){
        printf("%02d", order_number);
        printf(">%4s", the_order->customer);
        printf("%*s", space_pizza, the_order->pizza);
        printf("$%*0.2f", space_cost, the_order->cost);
        printf("%*20s\n", space_time, the_order->time);
    }

    else{
        printf("%02d", order_number);
        printf(" %4s", the_order->customer);
        printf("%*s", space_pizza, the_order->pizza);
        printf("$%*0.2f", space_cost, the_order->cost);
        printf("%*20s\n", space_time, the_order->time);
    }

}

I tried to follow Left-pad printf with spaces of the answer by Rece Foc and edit by joe pelletier.

int space = 40;

printf("%*s", space, "Hello");

printf("%*d", space, 10);

printf("%*c", space, 'x');

Before I tried this method I did this:

void print_order(struct order *the_order, int order_number, bool selected) {
    if (selected == true){
        printf("%02d >%4s %20s $%0.2f %20s\n", order_number, the_order->customer, the_order->pizza, the_order->cost, the_order->time);
    }

    else{
        printf("%02d  %4s %20s $%0.2f %20s\n", order_number, the_order->customer, the_order->pizza, the_order->cost, the_order->time);
    }
}

I am unsure what I am doing wrong here as I am unfamiliar with c and this way of printing values.

Answer 1

Here's a prototype that you can examine and 'tweak' to the column widths and using the data sources that you need.

The column widths should be easy to understand. The leading '-' on the '%s' definitions means "left justify in a field this wide".

Notice the trenary "? : " that sets the single character showing 'selected' to be either an empty SP or a GT symbol.

void print( bool selected ) {
    int ordNo = 42;
    char selchar = selected ? '>' : ' ';
    char *name = "Bob the Builder";
    char *pizza = "Meat Lovers";
    double cost = 25.75;
    char *time = "23:30:05"; // midnight munchies

    char *fmt = "%-4d %c%-35s%25s%13.2f%10s\n";

    printf( fmt, ordNo, selchar, name, pizza, cost, time );
}

int main() {
    print( false );
    print( true );

    return 0;
}

Output:

42    Bob the Builder                                  Meat Lovers        25.75  23:30:05
42   >Bob the Builder                                  Meat Lovers        25.75  23:30:05

Make fine adjustments to the column widths, then test, then make more fine adjustments until you get what you want/need...