Re: Glib problem: trying to use gpointer pointing to a structure in a GList. Getting segfault

[John Cupitt <john cupitt ng-london org uk>]

Hi, you're not allocating a record anywhere, you've just declared a pointer to one and not initialised it. Also, g_strdup() will save you a little code.

John


Lucas Brasilino wrote:
> #include <stdio.h>
> #include <string.h>
> #include <glib.h>
>
> int main(int argc, char **argv)
> {
>
>         GList *dlist = NULL, *list = NULL;
>         guint length,i;
>         struct {
>                 guint index;
>                 gchar *data;
>         } *record;

I'd do 

	typedef struct _Record {
		int index;
		char *data;
	} Record;

	Record *rp;

>         record->data = g_malloc(strlen("Lucas")+1);Lucas"
>         g_strlcpy(record->data,"Lucas",strlen("Lucas")+1);
>         dlist = g_list_append(dlist, record);

here do:

	rp = g_new( Record, 1 );
	rp->index = 0;
	rp->date = g_strdup( "Lucas" );
	dlist = g_list_append( dlist, rp );
	
>         record->data = g_malloc(strlen("Brasilino")+1);
>         g_strlcpy(record->data,"Brasilino", strlen("Brasilino")+1);
>         dlist = g_list_append(dlist, record);

same here


>         length = g_list_length(dlist);
>
>         g_printf("%d \n",length);
>
>         record = NULL;g_list_first(dlist)
>         list = g_list_first(dlist);
>         while(list)
>         {
>                 record = list->data;
>                 g_print("%s\n",record->data);
>                 list = list->next;

And change these to:

		rp = (Record *) list->data;
		printf( "index = %d, name = \"%s\"\n", rp->index, rp->data );
		list = list->next;

You could change the loop to:

	for( list = g_list_first( dlist ); list; list = list->next ) {
		rp = (Record *) list->data;
		printf( "index = %d, name = \"%s\"\n", rp->index, rp->data );
	}

which is slightly easier to read

>     }
> }
>
> ================