Added search function

Demonstration/book.c

@@ -33,3 +33,9 @@ void book_print(const void* data)
 	const Book* book = (Book*)data;
 	printf("Book[title=%s,author=%s,year=%d]\n", book->title, book->author, book->year);
 }
+
+int title_eq(const void* title, const void* data)
+{
+	Book* book = (Book*)data;
+	return !strcmp(book->title, (char*) title);
+}

Demonstration/book.h

@@ -9,3 +9,5 @@ typedef struct {
 Book* book_create(const char* title, const char* author, int year);
 
 void book_print(const void* data);
+
+int title_eq(const void* title, const void* data);

Demonstration/main.c

@@ -136,25 +136,48 @@ void show_print_pointers(Node** list)
 	list_print_pointers(*list);
 }
 
+void show_search(Node** list)
+{
+	char title[80];
+	Node* book;
+
+	printf("Enter the title to search for: ");
+	gets_s(title, 80);
+	book = list_search(*list, title, &title_eq);
+	if (book)
+		book_print(book->data);
+	else
+		puts("No list item matched the given title.");
+}
+
+#define item(NAME, KEY, FUNC) {NAME, KEY, (void*)&FUNC, &list}
+#define page(NAME, ARR) {ARR, sizeof(ARR) / sizeof(struct MenuItem), NAME, true, true, &SOLID}
+
 void main(void)
 {
 	Node* list = NULL;
 
-	struct MenuItem items[] = {
+	struct MenuItem items_modification[] = {
-		{"Push item", '1', (void*)&show_push, &list},
+		item("Push Item", '1', show_push),
-		{"Append item", '2', (void*)&show_append, &list},
+		item("Append item", '2', show_append),
-		{"Insert item", '3', (void*)&show_insert, &list},
+		item("Insert item", '3', show_insert),
-		{"Print item", '4', (void*)&show_print, &list},
+		item("Remove item by index", '4', show_remove),
-		{"Look at item by index", '5', (void*)&show_get, &list},
+		{"BLANK", ' ', NULL, NULL},
-		{"Remove item by index", '6', (void*)&show_remove, &list},
+		{"Quit", 'q', (void*)&exit, NULL}
-		{"READ", 'r', (void*)&show_read, &list},
+	};
-		{"RIDE", 'w', (void*)&show_write, &list},
+	struct MenuItem items_util[] = {
-		{"Print pointers", 'p', (void*)show_print_pointers, &list},
+		item("Print list", '1', show_print),
+		item("Print list element by index", '2', show_get),
+		item("Search for title", '3', show_search),
+		item("Read", 'r', show_read),
+		item("Write", 'w', show_write),
+		item("Print pointers", 'p', show_print_pointers),
 		{"BLANK", ' ', NULL, NULL},
 		{"Quit", 'q', (void*)&exit, NULL}
 	};
 	struct MenuPage pages[] = {
-		{items, sizeof(items) / sizeof(struct MenuItem), "Linked List Demo", true, true, &SOLID}
+		page("Linked List Modification", items_modification),
+		page("Linked List Utility", items_util),
 	};
 	show_menu(pages, sizeof(pages) / sizeof(struct MenuPage), true);
 }

Implementation/linked_list.c

@@ -86,6 +86,13 @@ Node* list_get(Node* head, unsigned index)
 	return head;
 }
 
+Node* list_search(Node* head, void* elem, int (*eq)(void*, void*))
+{
+	while (head && !eq(elem, head->data))
+		head = head->next;
+	return head;
+}
+
 void list_remove(Node* node)
 {
 	if (node->prev)

Implementation/linked_list.h

@@ -17,4 +17,6 @@ void list_insert(Node* prev_node, void* data);
 
 Node* list_get(Node* head, unsigned index);
 
+Node* list_search(Node* head, void* elem, int (*eq)(void*, void*));
+
 void list_remove(Node* node);