如何解決 c 中的填充問題？

Question

我正在努力做到這一點，以便無論變量的長度（例如，最大長度為16的char customer ）都將與標題Customer對齊，如下所示：

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

注意：我試圖以用戶輸入名稱變量的方式實現這一點，因此它的長度不同。

下面我在下面的代碼中遇到分段錯誤，不知道為什么：

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);
    }

}

我試圖跟隨Left-pad printf 和Rece Foc 的答案空格並由joepellier 編輯。

int space = 40;

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

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

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

在我嘗試這種方法之前，我這樣做了：

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);
    }
}

我不確定我在這里做錯了什么，因為我不熟悉 c 和這種打印值的方式。

Answer 1

這是一個原型，您可以檢查並“調整”列寬並使用所需的數據源。

列寬應該很容易理解。 '%s' 定義中的前導 '-' 表示“在這么寬的字段中左對齊”。

請注意三元組“？：”，它將顯示“已選擇”的單個字符設置為空 SP 或 GT 符號。

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

對列寬進行微調，然后進行測試，然后進行更多微調，直到獲得您想要/需要的...