Thread: linked list: properly freeing and reusing inside of loop??

Hello all; I haven't programmed anything in ages, and could use some help trying to recall how to properly initialize, free, and then reuse the same variables from within a loop. I'm working with a single linked list defined as

Code:

typedef struct __LLIST {
   char *data;
   struct __LLIST *next;
} list;

my variables are declared as

Code:

list base = { 0, 0 }, *node = &base, *tmp = 0;

Here's what I've tried; it *appears* to work on the first run but throws an exception on the next iteration of the control loop.

Code:

control loop {
   // prompt user for string
   // read string into static char array
   // split string using strtok: p = strtok(user_input, " ");
   
   while(p) {
      node->next = malloc(sizeof(*node));
      node = node->next;
      node->data = malloc(strlen(p) + 1);
      strcpy(node->data, p);
      node->next = 0;
      p = strtok(0, " ");
   }

   // do stuff with list
   // try to free and reuse it

   node = &base;
   tmp = 0;

   while(node) {
      tmp = node;
      free(node->data);
      node = node->next;
      free(tmp);
   }

   node = 0;
   tmp = 0;

   memset(&base, 0, sizeof(list));
   node = &base;
}

Any ideas/help would be greatly appreciated.

Lines 18, 22, and 25 amount to trying to call free on what must either be a global or local variable rather than a pointer.
That will do bad things

Thank you so much for the reply.

It just hurts to see how much I've forgotten... lists always gave me fits and they still haunt me it seems. I was about to shelve this idea and try my hand at using a vector instead.

Code:

    for( ; ; ) {

        node = &base;
        tmp = NULL;
    
        while(p) {
            // code unchanged
        }

        // *seems* to work or at least
        // runs without dying

        node = base.next;

        while(node) {
            // code unchanged
         }
    }

Cheers.