1 files changed, 53 insertions, 0 deletions
diff --git a/list.c b/list.c
new file mode 100644
index 0000000..578c61a
--- /dev/null
+++ b/list.c
@@ -0,0 +1,53 @@
+#include <stdlib.h>
+#include <string.h>
+#include "list.h"
+
+/* allocates and initialises list structure; returns NULL if malloc fails */
+struct list *list_create() {
+    struct list *list = malloc(sizeof(struct list));
+    if (list)
+	memset(list, 0, sizeof(struct list));
+    return list;
+}
+
+/* frees all memory associated with the list */
+void list_destroy(struct list *list) {
+    struct list_node *node, *next;
+    
+    for (node = list->first; node; node = next) {
+	free(node->data);
+	next = node->next;
+	free(node);
+    }
+    free(list);
+}
+
+/* appends entry to list; returns 1 if ok, 0 if malloc fails */
+int list_add(struct list *list, void *data) {
+    struct list_node *node;
+
+    node = malloc(sizeof(struct list_node));
+    if (!node)
+	return 0;
+    
+    node->next = NULL;
+    node->data = data;
+
+    if (list->first)
+	list->last->next = node;
+    else
+	list->first = node;
+    list->last = node;
+    
+    return 1;
+}
+
+/* returns first node */
+struct list_node *list_first(struct list *list) {
+    return list->first;
+}
+
+/* returns the next node after the argument */
+struct list_node *list_next(struct list_node *node) {
+    return node->next;
+}