display function for nested singly linked list c - c

Question

Im writing database program for my c class for few days now im trying to figure out how to work with singly linked lists its pretty hard to understand I would say ,well at least for me. Overall I got part of code necessary for my project, basicaly I got functions to add client and items to client thanks to help of somebody from stackoverflow I kinda figured how to add multiple items to 1 client but now I'm in trouble figuring out how exactly can I print it ,tried to do it the way you can see im my display function but it doesnt work for items linked to client what should I change to make it work?
#include <stdio.h>
#include <stdlib.h>
struct item{
char item_name[30];
struct item *NextItem;
};
struct client{
struct client *NextClient;
char name[30];
char last_name[30];
struct item *firstItem;
struct item *lastItem;
};
struct client *head = NULL;
/////////////////////////////
struct client* FindTailClient(struct client* head)
{
struct client *temp = head;
while( temp->NextClient != NULL)
{
temp = temp->NextClient;
}
return temp;
}
/////////////////////////////
////////
struct client *GetClientData()
{
char data[30];
struct client *temp;
temp = (struct client*)malloc(sizeof(struct client));
printf("Enter the person's name--->");
scanf("%s",data);
strcpy(temp->name,data);
printf("Enter the person's last name--->");
scanf("%s",data);
strcpy(temp->last_name,data);
temp->NextClient = NULL;
return temp;
}
///////////
struct item *GetItemData()
{
struct item *temp;
char data[30];
temp = (struct item*)malloc(sizeof(struct item));
printf("Enter the item name--->");
scanf("%s",data);
strcpy(temp->item_name,data);
temp->NextItem = NULL;
return temp;
}
///////////
//////////////
struct client* AddClient()
{
struct client *temp,temp1;
temp=head;
struct client *data = GetClientData();
if(head == NULL)
{
head=data;
head->NextClient = NULL;
}
else
{
while(temp->NextClient != NULL)
{
temp=temp->NextClient;
}
data->NextClient=NULL;
temp->NextClient=data;
}
}
///////////////////
///////////////////
///////////////////
void display()
{
struct client *CurrentClient = head;
struct item *ItemCurrent = head->firstItem;
while(CurrentClient != NULL)
{
printf(" -> %s ->%s \n",CurrentClient->name,CurrentClient->last_name);
while(ItemCurrent != NULL)
{
printf(" -> %s\n",ItemCurrent->item_name);
ItemCurrent=ItemCurrent->NextItem;
}
CurrentClient=CurrentClient->NextClient;
}
}
///////////////////
void AddItemToClient(struct client* head, struct item *item)
{
item->NextItem = NULL;
if(head->firstItem == NULL) {
head->firstItem = item;
} else {
head->lastItem->NextItem = item;
}
head->lastItem = item;
}
///////////////////
struct client *find(struct client *head, char name[])
{
while (head->NextClient != NULL )
{
if (strcmp(head->name,name) == 0)
{
printf("Target found: %s\n",head->name);
return head;
}
head = head->NextClient;
}
printf("target not found");
return NULL;
}
//////////////////
int main()
{
int i;
char data[30];
char name[30];
struct client *temp;
struct client *head;
struct item *data1;
for(i=0;i<2;i++)
{
AddClient();
}
printf("Insert name to find:");
scanf("%s",name);
temp = find(&head,name);
data1 = GetItemData();
AddItemToClient(temp,&data1);
display();
}

Answer 1

In this line: "while(ItemCurrent != ItemLast)" - ItemLast is undeclared. Maybe you wanted to write head->lastItem, or better ItemCurrent->next != NULL.
Also, make sure you store the clients you just created to be able to access them: head = AddClient(); instead of simply AddClient();