سؤال

I'm converting an array of integers into a char by iterating through the whole array, and then I'm adding the resulting string to ncurses's method new_item. For some reason I'm doing something wrong the way I reallocate memory, thus I get the the first column as:

-4 Choice 1                 0 Choice 1
 4 Choice 2                 1 Choice 1
 4 Choice 3  - Instead of - 2 Choice 1
 4 Choice 4                 3 Choice 1
 4 Exit                     4 Choice 1

-

#include <stdio.h>
#include <stdlib.h>
#include <curses.h>
#include <menu.h>

#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
#define CTRLD     4

char *choices[] = {
                        "Choice 1",
                        "Choice 2",
                        "Choice 3",
                        "Choice 4",
                        "Exit",
                  };
int table[5]={0,1,2,3,4}; 
int main()
{    ITEM **my_items;
    int c;              
    MENU *my_menu;
    int n_choices, i;
    ITEM *cur_item;

    initscr();
    cbreak();
    noecho();
    keypad(stdscr, TRUE);

    n_choices = ARRAY_SIZE(choices);
    my_items = (ITEM **)calloc(n_choices + 1, sizeof(ITEM *));

    char *convert = NULL;
    for(i = 0; i < n_choices; ++i){
        convert = (char *) malloc ( sizeof(char) * 4);
        sprintf(convert, "%i", table[i]); 
        my_items[i] = new_item(convert, choices[i]);
    }
    my_items[n_choices] = (ITEM *)NULL;

    my_menu = new_menu((ITEM **)my_items);
    mvprintw(LINES - 2, 0, "F1 to Exit");
    post_menu(my_menu);
    refresh();

    while((c = getch()) != KEY_F(1))
    {   switch(c)
        {   case KEY_DOWN:
                menu_driver(my_menu, REQ_DOWN_ITEM);
                break;
            case KEY_UP:
                menu_driver(my_menu, REQ_UP_ITEM);
                break;
        }
    }

    char *n = NULL, *d = NULL;

    unpost_menu(my_menu);
    free_menu(my_menu);
    for(i = 0; i < n_choices; ++i){
       n = (char *) item_name (my_items[i]);
       free (n);
       d = (char *) item_description (my_items[i]);
       free (d);
       free_item(my_items[i]);
    }

    free(my_items);
    endwin();
}

**Update: This has been fixed. See code above!

هل كانت مفيدة؟

المحلول

You attempt to realloc the same memory block with the same size again and again, for which realloc just returns the same memory block. So you are overwriting the earlier values of convert, and storing the same char array in all items.

You should use malloc instead:

// right here
char *convert = NULL;
for(i = 0; i < n_choices; ++i){
    convert = (char *) malloc (sizeof(char) * 4);
    sprintf(convert, "%i", table[i]); 
    my_items[i] = new_item(convert, choices[i]);
}
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