initial commit

llist.c

@@ -0,0 +1,212 @@
+#include "llist.h"
+#include <stdio.h>
+
+List *create_list(void *data)
+{
+    ListNode *new_node;
+
+    List *new_list = (List *) malloc(sizeof(List));
+    *new_list = (ListNode *) malloc(sizeof(ListNode));
+
+    new_node = *new_list;
+    new_node->data = data;
+    new_node->next = NULL;
+
+    return new_list;
+}
+
+List *list_remove(List *list, uint32_t position)
+{
+    ListNode *head;
+    ListNode *current;
+    ListNode *tmp;
+
+    if (list == NULL || *list == NULL)
+    {
+        return list;
+    }
+
+    if (position == 0)
+    {
+        head = *list;
+        head = head->next;
+        *list = head;
+        return list;
+    }
+
+    if (position >= list_size(list))
+    {
+        current = *list;
+        while(current->next)
+        {
+            tmp = current;
+            current=current->next;
+        }
+
+        tmp->next = NULL;
+        free(current);
+
+        return list;
+    }
+
+    current = *list;
+    tmp = current;
+    while (current && position > 0)
+    {
+        tmp = current;
+        current = current->next;
+        position--;
+    }
+
+    tmp->next = current->next;
+    free(current);
+
+    return list;
+}
+
+List *list_add(List *list, void *data, uint32_t position)
+{
+    ListNode *new_node;
+    ListNode *head;
+    ListNode *current;
+
+    if (list == NULL || *list == NULL)
+    {
+        return NULL;
+    }
+
+    head = *list;
+
+    if (head == NULL)
+    {
+        head->data = data;
+        head->next = NULL;
+        return list;
+    }
+
+    new_node = (ListNode*) malloc(sizeof(ListNode));
+    new_node->data = data;
+
+    if (position == 0)
+    {
+        new_node->next = *list;
+        *list = new_node;
+        return list;
+    }
+
+    if (position >= list_size(list))
+    {
+        current = *list;
+        while (current->next)
+        {
+            current = current->next;
+        }
+        current->next = new_node;
+        return list;
+    }
+
+    /* add at any position */
+    current = *list;
+    while (current && position-- >1)
+    {
+        current = current->next;
+    }
+
+    ListNode *tmp = current->next;
+    current->next = new_node;
+    new_node->next = tmp;
+
+    return list;
+}
+
+void print_list(List *list)
+{
+    ListNode *current;
+    uint32_t index = 0;
+
+    if (list == NULL || *list == NULL)
+        return;
+
+    current = *list;
+
+    while (current)
+    {
+        printf("At %d value = %p\n", index, current);
+        index++;
+        current = current->next;
+    }
+}
+
+void list_delete(List *list)
+{
+    ListNode *current;
+    ListNode *next;
+
+    if (list == NULL || *list == NULL)
+        return;
+
+    current = *list;
+    while (current->next)
+    {
+        next = current->next;
+        free(current);
+        current = next;
+    }
+
+    free(list);
+}
+
+uint32_t list_size(List *list)
+{
+    uint32_t size = 0;
+    ListNode *current;
+
+    if (list == NULL || *list == NULL)
+        return size;
+
+    current = *list;
+    while (current)
+    {
+        size++;
+        current = current->next;
+    }
+
+    return size;
+}
+
+void print_size_and_list(List *list)
+{
+    printf("size = %d\n", list_size(list));
+    print_list(list);
+}
+
+int main(int argc, char **argv)
+{
+    void *new_data  = (void *) malloc(sizeof(void));
+    void *new_data2 = (void *) malloc(sizeof(void));
+    void *new_data3 = (void *) malloc(sizeof(void));
+    void *new_data4 = (void *) malloc(sizeof(void));
+
+    List *new_list = create_list(new_data);
+    print_size_and_list(new_list);
+
+    list_add(new_list, new_data2, 0);
+    print_size_and_list(new_list);
+
+    list_add(new_list, new_data3, 3);
+    print_size_and_list(new_list);
+
+    list_add(new_list, new_data4, 2);
+    print_size_and_list(new_list);
+
+    list_remove(new_list, 2);
+    print_size_and_list(new_list);
+
+    list_delete(new_list);
+    new_list = NULL;
+
+    print_size_and_list(new_list);
+
+   return 0;
+}
+

llist.h

@@ -0,0 +1,34 @@
+/*
+ * llist.h
+ * Generic linked list implementation in C
+ */
+#ifndef __LLIST_H__
+#define __LLIST_H__
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define container_of(ptr, type, member) ({                      \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
+        (type *)((char *)__mptr - offsetof(type,member));})
+
+
+typedef struct ListNode{
+    void *data;
+    struct ListNode *next;
+} ListNode;
+
+typedef ListNode * List;
+
+List *create_list(void *data);
+
+uint32_t list_size(List *list);
+
+List *list_add(List *list, void *data, uint32_t position);
+
+List *list_remove(List *list, uint32_t position);
+
+void list_delete(List *list);
+
+#endif /* __LLIST_H__ */