| Create cache / Initialize | lru_create(int capacity) | Allocate and initialize cache structure, hash table, and dummy head/tail nodes for the doubly linked list. |
| Free cache / Cleanup | lru_free(LRUCache *c) | Free all nodes, free hash table and cache structure; ensure no memory leaks. |
| Visit / Put (cache page) | lru_put(LRUCache *c, const char *url, const char *content) | Insert a URL and its content into cache; if key exists update content and move node to MRU; if capacity exceeded pop LRU and evict (remove from DLL and hash). |
| Access / Get (load page) | lru_get(LRUCache *c, const char *url) | Look up URL in hash table; on hit move node to MRU (front of DLL) and return content; on miss return NULL. |
| Eviction (LRU remove) | dll_pop_tail, hash_remove (used inside lru_put) | Remove least-recently-used node from DLL and remove its entry from hash table; free node memory. |
| Doubly linked-list helpers | dll_add_to_head, dll_remove, dll_move_to_head, dll_pop_tail | Manipulate DLL for recency ordering (insert at head, remove node, promote node, pop tail). |
| Hash-table helpers | hash_string, hash_find, hash_insert, hash_remove | Compute bucket index, lookup node by URL, insert node into hash chain, and remove node from chain. |
| Node management | free_node, xstrdup | Create/duplicate string memory safely and free node contents. |
| Display cache state | lru_print(LRUCache *c) | Print current cache entries from most- to least-recently-used for debugging / report screenshots. |
| View page content | print_page(const char *url, const char *content) | Pretty-print page content when a cached URL is loaded. |
| Demo scenario | demo_scenario(LRUCache *c) | A scripted sequence of puts and gets to demonstrate cache behavior (used for screenshots / testing). |
| Console UI & input helpers | main(), read_line, trim | Menu loop (visit/access/show/demo/exit) and safe input reading/trimming for user interaction. |
