Re: How to use GList Double Link List

[Matí­as Alejandro Torres <torresmat gmail com>]

sumit kumar escribió:
> *gint pos;
> g_print("Enter Number1\n");
> scanf("%d",&pos);
> list = g_list_append(list, (gpointer)&pos);
>
> g_print("Enter Number2\n");
> scanf("%d",&pos);
> list = g_list_append(list, (gpointer)&pos);
>
> g_print("Enter Number3\n");
> scanf("%d",&pos);
> list = g_list_append(list, (gpointer)&pos);
>
> g_print("Enter Number4\n");
> scanf("%d",&pos);
> list = g_list_append(list, (gpointer)&pos);
> *
> It prints only last element I appened 4 times... 44, 44 ,44 ,44 if I
> appended 44 as last element.
> Whats wrong with this code??
>
>   
You're not alocating new space, the pos pointer is always pointing at 
the same cell, which by the way is never initialized. Also, when you use 
g_list_append you're passing a pointer to a pointer to an integer, and I 
don't think that's what you want. Do something like:

#include <stdio.h>
#include <glib.h>
#include <glib/gprintf.h>

int main (int argc, char **argv) {
        GList *tmp, *list = NULL;
        gint i, *element;
        
        /* Appends 4 integers into list */
        for (i=1; i<5; i++) {
                element = g_malloc (sizeof (gint));
                g_printf ("Enter Number %d: ", i);
                scanf ("%d", element);
                list = g_list_append (list, element);
        }
        
        /* Prints data in list */
        tmp = list;
        while (tmp) {
                element = tmp->data;
                g_printf ("%d\n", *element);
                tmp = g_list_next (tmp);
        }
        
        /* Frees the data in list */
        tmp = list;
        while (tmp) {
                g_free (tmp->data);
                tmp = g_list_next (tmp);
        }
        
        /* Frees the list structures */
        g_list_free (list);
        
        return 0;
}

GLib API Reference: http://developer.gnome.org/doc/API/2.0/glib/index.html
GLib Tutorial: http://gtk.org/tutorial/x2037.html