PSET 5 SPELLER - segmentation fault

Question

I keep getting a segmentation fault on my load function when using the debugger. Specifically, the line with "if(table[num]->next != NULL)" is what is causing it. I need some help, please.

bool load(const char *dictionary)
{
    unsigned int num = 0;

    char buffer[LENGTH + 1];

   //Open dictionary file

   FILE* ptr = fopen(dictionary, "r");

   if(ptr == NULL)

   {
       printf("Can't open dictionary");

       return false;
   }

    //Read string from file one at a time
    while(fscanf(ptr,"%s",buffer) != EOF)
    {
        //Create a new node for each word
        node* n =malloc(sizeof(node));

        if(n != NULL)
        {
            strcpy(n->word,buffer);
            n->next = NULL;
        }
        //Hash word to obtain a hash value for each word
        num = hash(buffer);


        //Check to see if something already at location
        if(table[num]->next != NULL)
        {

             n->next = table[num];
        }
        //Insert node into hash table at that location
        table[num] = n;

        //keeps track of how many words in dictionary
        count++;

        free(n);
    }

    return false;
}

Answer 1

I see two problems here. First, table[] isn't initialized before being used. Second, looking specifically at your line of code, if table[num] doesn't exist (is NULL) or still contains garbage(not initialized), then table[num]->next doesn't exist, so it will throw a seg fault.