Unable to iterate the linked list in C - c

Question

I am trying to print all the members of a linked list. I am traversing the list and counting the duplicate copies of the integers in the list if any. But when I traverse the list again to check for duplicate copies, my ipNext points to null terminating my previous traverse loop.
Inserting data function:
void insertIP(bstNode *head, char user[], int ip){
if(head != NULL){
bstNode* startList = head;
while ((startList) && (strcmp(startList->data, user) != 0) ){
if(strcmp(user, startList->data)<0)
{
startList=startList->left;
}
else if(strcmp(user, startList->data)>0)
{
startList=startList->left;
}
}
if (startList != NULL){
IP* new = (IP*)malloc(sizeof(IP));
new->ip = ip;
//new->count = (new->count + 1);
new->ipNext=NULL;
IP* temp = startList->ipHead;
startList->ipHead = new;
new->ipNext = temp;
}
}
}
Iteration function which looks for a specific data entry and count the occurences of it in the linked list if any.
bstNode* search(char* key, bstNode* root)
{
int res;
bstNode *leaf = root;
if( leaf != NULL ) {
res = strcmp(key, leaf->data);
if( res < 0)
search( key, leaf->left);
else if( res > 0)
search( key, leaf->right);
else
{
printf("\n'%s' found!\n", key);
//int count = 0;
bstNode *temp = leaf;
while (temp->ipHead != NULL) {
int tempip = temp->ipHead->ip;
int ipcount = 0;
uint32_t ip = tempip;
struct in_addr ip_addr;
ip_addr.s_addr = ip;
bstNode *cpy = leaf;
ipcount = count(&cpy, tempip);
//temp = leaf;
printf("The IP address is %s\n C:%d\n", inet_ntoa(ip_addr), ipcount);
temp->ipHead = temp->ipHead->ipNext;
}
}
}
else printf("\nNot in tree\n");
return leaf;
}
Supporting function (This set the ipNext value to null which terminates the loop in search. Even though I am passing a copy of the pointer, I think that is my problem).
int count(bstNode** start, int item)
{
bstNode* current = *start;
int count = 0;
while (current->ipHead->ipNext != NULL)
{
if (current->ipHead->ip == item)
{
count++;
}
current->ipHead = current->ipHead->ipNext;
}
return count;
}
The data structure decleration:
typedef struct ip{
int ip;
struct ip *ipNext;
}IP;
typedef struct bstNode
{
char data[32];
struct bstNode* left;
struct bstNode* right;
IP *ipHead;
}bstNode;
BST insert function:
bstNode *insert(bstNode *root, char *word, int ip)
{
bstNode *node = root;
if(node==NULL){
node= malloc(sizeof(bstNode));
//IP* ipNode=malloc(sizeof(IP));
strcpy(node->data, word);
node->left=NULL;
node->right=NULL;
insertIP(node, word, ip);
}
else{
if(strcmp(word, node->data)<0)
node->left=insert(node->left, word, ip);
else if(strcmp(word, node->data)>0)
node->right=insert(node->right, word,ip);
else if(strcmp(word, node->data) == 0) {
insertIP(node, word, ip);
}
}
return node;
}
I appreciate everyones help!

Answer 1

As pointed out in the comments, here is your problem:
while ((startList) && (strcmp(startList->data, user) != 0) ){
if(strcmp(user, startList->data)<0)
{
startList=startList->left;
}
else if(strcmp(user, startList->data)>0)
{
startList=startList->left;
}
}
You are taking the left path in both cases. I wouldn't post this as an answer (since it is already answered in the comments by Pras, but when I see this kind of non-optimized code, it bothers me: You may call the strcmp() function several times with the same data and the result will always be the same. strcmp() may be a costly operation if long strings are compared and besides you are doing this inside of a tree, so this operation could be performed A LOT of times. So why don't you assign the result in a variable the first time and then test the result, not call the strcmp() again. Like:
int result;
while (startList && (result = strcmp(startList->data, user)) ) {
if (result < 0)
{
startList = startList->left;
}
else if (result > 0)
{
startList = startList->right;
}
}
Actually the second if is not needed, you may use a simple else because the test for zero is done in the condition of the while statement, so apparently if the result is not < 0, it will be > 0 for sure.