Having trouble creating a linked list - c

Question

Sorry for the vague title, i'm not quite sure how to explain what is going on. I am attempting to create a linked list, with each entry of the linked list containing two character strings, one integer array that can hold four entries, and one float array that can hold four entries.
Here is the initialization of the main struct in a header file -
#ifndef FUNCTIONS_H
#define FUNCTIONS_H
#define MAX_LENGTH 20
struct stock {
char ticker[MAX_LENGTH];
char comp[MAX_LENGTH];
int shares[4];
float price[4];
struct stock *next;
};
#endif
Here is the code from my main file -
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "functions.h"
void main(void) {
int choice,shr[4], i;
char tic[MAX_LENGTH];
char nam[MAX_LENGTH];
float pri[4];
struct stock *head = NULL;// entry point for linked list
struct stock *current; //pointer currently being used
printf("Press 1 to enter a new stock\n");
printf("Press 2 to find the LIFO and FIFO dollar cost average for the number of shares sold\n");
scanf("%d", &choice);
switch(choice)
{
case 1:
printf("Enter the stock ticker:\n");
scanf("%s", &tic);
printf("Enter the name of the stock:\n");
scanf("%s", &nam);
for(i = 1; i<=4; i++) {
printf("Enter the number of shares:\n");
scanf("%d",&shr[i] );
printf("Enter the price of the stock:\n");
scanf("%f", &pri[i]);
}
if(head == NULL) { //check to see if first element has been filled
head = (struct stock *)malloc(sizeof(struct stock));
current = head;
}
else { //if the first element is full, move on to the next entry
current->next = (struct stock *)malloc(sizeof(struct stock));
current = current->next;
}
strcpy(current->ticker, tic);
strcpy(current->comp, nam);
memcpy(current->shares, shr, sizeof(current->shares));
memcpy(current->price, pri, sizeof(current->price));
current->next = NULL;
}
printf("%s\n", current->ticker);
printf("%s\n", current->comp);
for(i = 1; i <= 4; i++) {
printf("%d\n", current->shares[i]);
printf("%f\n", current->price[i]);
}
}
The end goal of the program is to have two separate stock entries, and be able to calculate the FIFO/LIFO dollar cost average based on four different share purchases for each stock. But for now, i am only trying to be able to correctly enter the information into a linked list.
After the loop that asks the user four times for the number of shares, and price of a stock, the character string "nam" asked for previously seems to disappear, because if i try to access it or print it out later it prints nothing.
I am trying to use the memcpy function to copy an inputted array over to the one in the linked list. Whenever i try to print the array back out after i copied it to the linked list, it does not print properly. The first three entries of the shares and price arrays print properly, but the fourth share entry prints a huge number and the fourth float entry prints as zero.
Thanks for any help.

Answer 1

tic and nam are already pointers so change
scanf("%s", &tic);
scanf("%s", &nam);
to
scanf("%s", tic);
scanf("%s", nam);
Also, not directly related to your issue, but
head = (struct stock *)malloc(sizeof(struct stock));
current->next = (struct stock *)malloc(sizeof(struct stock));
would be better written as
head = malloc(sizeof(*head));
current->next = malloc(sizeof(*(current->next)));
There is no need to cast the return from malloc() and by using sizeof(*head) you are guaranteed to be using the correct type for sizeof.