Thread: Why my singly linked-list program doesn't run?

It sounds like you're confusing the notion of a linked list with that of the nodes of the linked list. What you are trying to do is to have one linked list with multiple nodes, and so you ask the user how many students should be in the list.

Note that <malloc.h> is pre-standard; just #include <stdlib.h> for malloc and free.

I suggest that you work along these lines:

Code:

#include <stdio.h>
#include <stdlib.h>

struct student
{
    int id, age, choice;
    char name[30];
};

struct node
{
    struct student student_data;
    struct node *next;
};

struct node *prependNode(struct node *head);
/*void removeNextNode(struct node *node);*/

struct node *createList(void);

int main(void)
{
    struct node *head = NULL;
    int choice;

    printf("Please select an option: ");
    printf("1. Create\n");
/*  printf("2. Display\n");
    printf("3. Insert\n");
    printf("4. Remove\n");
    printf("5. Search");
    printf("6. Exist");*/
    scanf("%d", &choice);

    switch(choice)
    {
    case 1:
        head = createList();
        break;
    }

    return 0;
}

/* ... */

The idea is that you have a function like prependNode whose sole purpose is to prepend a node to the linked list given the head of the linked list, and return a pointer to the new node (i.e., the new head node of the linked list). This function could work even when the head node is a null pointer, i.e., it can be used to implement createList. createList itself is not concerned with the nitty gritty of getting the linked list functionality to work, no, it is concerned with requesting input from the user and using that to create the linked list with the help of prependNode. It finally returns the head node of the linked list so that it can be updated in the main function.

Doing things this way, you have a function for each of your options, but (except maybe for display) they never directly deal with the linked list, instead calling a function that doesn't do interactive I/O whose sole purpose is to deal with the linked list through the head node or some other node.

Oh, and remember to free what you malloc: this could mean having a destroyLinkedList function that takes the head node pointer and repeatedly calls free on the nodes of the linked list.