Tests for singly linked list

0-main.c

/**
 * Tests for singly linked list
 */

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

/* singly link list node */
typedef struct _node
{
    int data;
    struct _node *next;
} node;

/* return the middle node of the list.
 * - The length of the list is odd:  the middle node is list[(length + 1) /2]
 * - The length of the list is even: the middle node is list[(length) /2]
 */
static node* list_get_middle_node(node *hdr)
{
    node *slow_ptr = hdr;
    node *fast_ptr = hdr;
    if (NULL == hdr)
    {
        return NULL;
    }

    for (; NULL != fast_ptr && NULL != fast_ptr->next;)
    {
        fast_ptr = fast_ptr->next->next;
        slow_ptr = slow_ptr->next;
    }
    return slow_ptr;
}

/* inserts a new element at the beginning of the list. */
static node* list_push_front(node *hdr, int data)
{
    node *item = (node *)malloc(sizeof(node));
    assert(NULL != item);
    item->data = data;
    item->next = hdr;
    return item;
}

/* free all node */
static void list_free(node *hdr)
{
    node *item;
    for (item = hdr; NULL != item; )
    {
        hdr = hdr->next;
        free(item);
        item = hdr;
    }
}

int main(int argc, char **argv)
{
    node *root = NULL;
    node *middle_node = NULL;

    /* prepare test list */
    root = list_push_front(root, 1);
    root = list_push_front(root, 2);
    root = list_push_front(root, 3);
    root = list_push_front(root, 4);
    root = list_push_front(root, 5);
    root = list_push_front(root, 6);
    root = list_push_front(root, 7);

    /* get and print the middle node */
    middle_node = list_get_middle_node(root);
    printf("Middle node %d\n", NULL == middle_node ? -1 : middle_node->data);

    /* free the list */
    list_free(root);
    root = NULL;
    return 0;
}

CMakeLists.txt

# CMake build script (read .ini) 
cmake_minimum_required(VERSION 2.8)

# project name & version
project(LinkedList)

include_directories("${PROJECT_SOURCE_DIR}")

# application
add_executable(linkedlist-test
    "${PROJECT_SOURCE_DIR}/0-main.c")

# install
install(TARGETS linkedlist-test DESTINATION bin)