Problem extracting data from a large file and passing it to a linked list

[medeshago]

Every time I try to extract data from a file that I have, it extracts the 2 first numbers and then it throws me a Segmentation fault. Here's the code of the two functions that are used:

void extraer()
{
	primer = ult = NULL;          //primer = first node ; ult = last node;
	int numero;

	FILE *fichero;
	fichero=fopen("datos.txt", "r");

	if (fichero==NULL)
	{
		printf("\nEl fichero no existe\n");
		menu();
	}

	while(!feof(fichero))
	{
		struct lista *neue;
		neue = new lista;
		fscanf(fichero, "%d", &numero);
		neue->id=numero;
		metelist(neue);                    //Inserts the node with the value into the list
	}
	fclose(fichero);
}

void metelist(struct lista *neue)              //Pushes the node into the linked list
{
     if(primer==NULL)
     {
          primer = neue;
          ult = neue;
     }
     else
     {
          primer->next = neue;
          ult = ult->next;
     }
     neue->next = NULL;
     ult->next = NULL;
}

When I try to run it, it extracts the first 2 numbers and then I get a Segmentation fault, and gdb says this:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000400fae in metelist(lista*) ()

I'm sorry if it's a noobish question.

[Bayint Naung]

Question 12.2

neue = new lista;

is it C or C++? Choose only ONE. and post to the correct forum next time.

[quzah]

void metelist(struct lista *neue)              //Pushes the node into the linked list
{
     if(primer==NULL)
     {
          primer = neue;
          ult = neue;
     }
     else
     {
          primer->next = neue;
          ult = ult->next;
     }
     neue->next = NULL;
     ult->next = NULL;
}

If I look at this, I assume that primer is the head of your list. This code either puts the new node as the head, if there isn't one, or it puts this node as the primer->next node, completely ignoring if there is already a primer->next. This I think should instead just be:

void foo( struct node *n )
{
    n->next = primer;
    primer = n->next;
}

Or something? I'm not sure what you are really thinking you're doing here, but I'm pretty sure you're doing it wrong.


Quzah.