server06 start

.idea/dictionaries/project.xml

@@ -2,6 +2,7 @@
   <dictionary name="project">
     <words>
       <w>mintime</w>
+      <w>wsock</w>
     </words>
   </dictionary>
 </component>

CMakeLists.txt

@@ -15,6 +15,7 @@ add_executable(server00 server00.c
 target_link_libraries(server00 wsock32 ws2_32)
 
 find_package(json-c CONFIG REQUIRED)
+find_package(PCRE2 CONFIG REQUIRED 8BIT)
 
 
 add_executable(server01 server01.c
@@ -26,5 +27,13 @@ target_link_libraries(server01 PRIVATE wsock32 ws2_32 json-c::json-c)
 
 add_executable(server02 server02.c server02.h ${COMMON_SOURCES})
 target_link_libraries(server02 wsock32 ws2_32)
+
 add_executable(server03 server03.c server03.h ${COMMON_SOURCES})
 target_link_libraries(server03 wsock32 ws2_32)
+
+add_executable(server04 server04.c server04.h ${COMMON_SOURCES})
+target_link_libraries(server04 wsock32 ws2_32)
+add_executable(server05 server05.c server05.h ${COMMON_SOURCES})
+target_link_libraries(server05 wsock32 ws2_32 PCRE2::8BIT)
+add_executable(server06 server06.c server06.h ${COMMON_SOURCES})
+target_link_libraries(server06 wsock32 ws2_32 PCRE2::8BIT)

client_connection_manager.py

@@ -0,0 +1,83 @@
+import socket
+import time
+
+def print_bytes(prefix, data):
+    """Print raw bytes with both hex and ASCII representation"""
+    hex_data = ' '.join(f'{b:02x}' for b in data)
+    ascii_data = ''.join(chr(b) if 32 <= b <= 126 else '.' for b in data)
+    print(f"{prefix} (hex): {hex_data}")
+    print(f"{prefix} (ascii): {ascii_data}")
+
+def create_client(name):
+    """Create and connect a client, handle initial connection sequence"""
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.connect(('localhost', 40000))
+    
+    # Receive welcome message
+    welcome = sock.recv(1024)
+    print(f"\n=== {name} receiving welcome message ===")
+    print_bytes("Received", welcome)
+    
+    # Send username
+    username = f"{name}\n".encode('ascii')
+    print(f"\n=== {name} sending username ===")
+    print_bytes("Sending", username)
+    sock.send(username)
+    
+    # Receive room info
+    room_info = sock.recv(1024)
+    print(f"\n=== {name} receiving room info ===")
+    print_bytes("Received", room_info)
+    
+    return sock
+
+def main():
+    # Create first client
+    print("\nConnecting client 1...")
+    client1 = create_client("Alice")
+    
+    time.sleep(1)  # Small delay between connections
+    
+    # Create second client
+    print("\nConnecting client 2...")
+    client2 = create_client("Bob")
+    
+    # Client 1 should receive notification about client 2
+    join_notification = client1.recv(1024)
+    print("\n=== Alice receiving Bob's join notification ===")
+    print_bytes("Received", join_notification)
+    
+    # Client 1 sends a message
+    message1 = "Hello Bob!\n".encode('ascii')
+    print("\n=== Alice sending message ===")
+    print_bytes("Sending", message1)
+    client1.send(message1)
+    
+    # Client 2 receives the message
+    received1 = client2.recv(1024)
+    print("\n=== Bob receiving message ===")
+    print_bytes("Received", received1)
+    
+    # Client 2 sends a reply
+    message2 = "Hi Alice!\n".encode('ascii')
+    print("\n=== Bob sending message ===")
+    print_bytes("Sending", message2)
+    client2.send(message2)
+    
+    # Client 1 receives the reply
+    received2 = client1.recv(1024)
+    print("\n=== Alice receiving message ===")
+    print_bytes("Received", received2)
+    
+    # Close connections
+    print("\nClosing connections...")
+    client1.close()
+
+    received1 = client2.recv(1024)
+    print("\n=== Bob receiving message ===")
+    print_bytes("Received", received1)
+
+    client2.close()
+
+if __name__ == "__main__":
+    main()

data.c

@@ -13,7 +13,25 @@ SOCKET get_listen_socket() {
     SOCKADDR_IN serverAddr;
 
     WSAStartup(MAKEWORD(2,0), &WSAData);
-    SOCKET server = socket(AF_INET, SOCK_STREAM, 0);
+    SOCKET server = socket(AF_INET, SOCK_STREAM, 0 );
+
+    serverAddr.sin_addr.s_addr = INADDR_ANY;
+    serverAddr.sin_family = AF_INET;
+    serverAddr.sin_port = htons(PORT);
+
+    bind(server, (SOCKADDR *)&serverAddr, sizeof(serverAddr));
+    listen(server, 0);
+    return server;
+}
+
+
+SOCKET get_listen_socket_udp() {
+    WSADATA WSAData;
+
+    SOCKADDR_IN serverAddr;
+
+    WSAStartup(MAKEWORD(2,2), &WSAData);
+    SOCKET server = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
     serverAddr.sin_addr.s_addr = INADDR_ANY;
     serverAddr.sin_family = AF_INET;
@@ -99,6 +117,11 @@ char *char_array_get_until_char(char_array_t *array, char c) {
     return ret;
 };
 
+void char_array_put_until_char(char *arr, char_array_t *array, char c) {
+    char *data = char_array_get_until_char(array, c);
+    memcpy(arr, data, strlen(data));
+}
+
 char *char_array_get_bytes(char_array_t *array, size_t length) {
     if (length > array->size) {
         return NULL;

data.h

@@ -22,6 +22,7 @@ void char_array_print_hex(const char_array_t *array);
 void char_array_wipe(char_array_t *array);
 bool char_array_has_char(char_array_t *array, char c);
 char *char_array_get_until_char(char_array_t *array, char c);
+void char_array_put_until_char(char *arr, char_array_t *array, char c);
 char *char_array_get_bytes(char_array_t *array, size_t length);
 void char_array_shift_bytes(char_array_t *array, size_t length);
 
@@ -35,3 +36,4 @@ void byte_array_shift_bytes(byte_array_t *array, size_t length);
 
 
 SOCKET get_listen_socket();
+SOCKET get_listen_socket_udp();

server03.c

@@ -30,7 +30,7 @@ int main() {
         handle_args_t *args = malloc(sizeof(handle_args_t));
         args->client = client;
         args->connection = connection_number++;
-        args->connections = *connections;
+        args->connections = connections;
         pthread_t thread;
         pthread_create(&thread, nullptr, handle_connection, args);
     }
@@ -42,51 +42,74 @@ void *handle_connection(void *args) {
     handle_args_t *handleArgs = args;
     char buffer[1024] = {0};
     int bytesReceived;
-    char *message[1024];
+    status_t status = CONNECTED;
+    char *message = malloc(sizeof(char)*1024);
     char_array_t *data = char_array_create(1024);
-    send(handleArgs->client, WELCOME, sizeof(WELCOME), 0);
+    send(handleArgs->client, WELCOME, sizeof(WELCOME)-1, 0);
-    bytesReceived = recv(handleArgs->client, buffer, sizeof(buffer), 0);
+    char *username = malloc(sizeof(char)*1024);
-    char_array_append(data, buffer, bytesReceived);
-    char *username = char_array_get_until_char(data, '\n');
-    if (username == NULL) {
-        printf("{%d} Failed to parse username\n", handleArgs->connection);
-        connections_remove(&handleArgs->connections, handleArgs->client);
-        free(handleArgs);
-        exit(3);
-    }
-    username = trim(username);
-    if (!username_is_valid(username)) {
-        printf("{%d} Invalid username\n", handleArgs->connection);
-        connections_remove(&handleArgs->connections, handleArgs->client);
-        free(handleArgs);
-        exit(3);
-    }
-    pthread_mutex_lock(&mutex);
-    strcat(message, "* The room contains: ");
-    for (int i = 0; i < handleArgs->connections.size; i++) {
-        strcat(message, handleArgs->connections.clients[i].username);
-        strcat(message, " ");
-    }
-    message[strlen(message)-1] = '\n';
-    send(handleArgs->client, message, strlen(message), 0);
-    pthread_mutex_unlock(&mutex);
-
-    connections_append(&handleArgs->connections, handleArgs->client, username);
-    sprintf(message, "* %s has entered the room\n", username);
-    broadcast(&handleArgs->connections, &handleArgs->client, message);
-
-    printf("{%d} Username: %s\n", handleArgs->connection, username);
-
     while ((bytesReceived = recv(handleArgs->client, buffer, sizeof(buffer), 0)) > 0) {
         printf("{%d} Client sent: |%d| \n", handleArgs->connection, bytesReceived);
         char_array_append(data, buffer, bytesReceived);
+        switch (status) {
+            case CONNECTED: {
+                if  ((username = char_array_get_until_char(data, '\n')) != NULL) {
+                    printf("{%d} Username raw: %s\n", handleArgs->connection, username);
+                    if (username == NULL) {
+                        printf("{%d} Failed to parse username\n", handleArgs->connection);
+                        closesocket(handleArgs->client);
+                        free(handleArgs);
+                        pthread_exit(NULL);
+                        exit(3);
+                    }
+                    username = trim(username);
+                    printf("{%d} Username after trim: %s\n", handleArgs->connection, username);
+                    if (!username_is_valid(username)) {
+                        printf("{%d} Invalid username\n", handleArgs->connection);
+                        closesocket(handleArgs->client);
+                        free(handleArgs);
+                        pthread_exit(NULL);
+                        exit(3);
+                    }
+                    pthread_mutex_lock(&mutex);
+                    sprintf(message, "* The room contains: ");
+                    for (int i = 0; i < handleArgs->connections->len; i++) {
+                        strcat(message, handleArgs->connections->clients[i].username);
+                        strcat(message, " ");
+                    }
+                    strcat(message, "\n");
+                    send(handleArgs->client, message, strlen(message), 0);
+                    pthread_mutex_unlock(&mutex);
+
+                    connections_append(handleArgs->connections, handleArgs->client, username);
+                    sprintf(message, "* %s has entered the room\n", username);
+                    broadcast(handleArgs->connections, &handleArgs->client, message);
+
+                    printf("{%d} Username: %s\n", handleArgs->connection, username);
+                    status = IDENTIFIED;
+                }
+                break;
+            }
+            case IDENTIFIED: {
                 char *request;
                 while ((request = char_array_get_until_char(data, '\n')) != NULL) {
                     sprintf(message, "[%s] %s\n", username, request);
+                    broadcast(handleArgs->connections, &handleArgs->client, message);
+                }
+                break;
             }
-        memset(buffer, 0, sizeof(buffer));
         }
 
+
+        memset(buffer, 0, sizeof(buffer));
+    }
+    if (status == IDENTIFIED) {
+        sprintf(message, "* %s has left the room\n", username);
+        broadcast(handleArgs->connections, &handleArgs->client, message);
+    }
+    connections_remove(handleArgs->connections, handleArgs->client);
+    printf("{%d} Client disconnected\n", handleArgs->connection);
+
+    free(message);
     free(args);
     return NULL;
 }
@@ -94,6 +117,7 @@ void *handle_connection(void *args) {
 connections_t *connections_create(const int size) {
     connections_t *connections = malloc(sizeof(connections_t));
     connections->size = size;
+    connections->len = 0;
     connections->clients = calloc(size, sizeof(client_connection_t));
     return connections;
 }
@@ -106,8 +130,8 @@ void connections_append(connections_t *connections, SOCKET client, char *usernam
         exit(1);
     }
     pthread_mutex_lock(&mutex);
-    size_t new_size = connections->size + 1;
+    size_t new_len = connections->len + 1;
-    if (new_size > connections->size) {
+    if (new_len > connections->size) {
         connections->size = connections->size+64;
         client_connection_t *new_array = realloc(connections->clients, connections->size * sizeof(client_connection_t));
         connections->clients = new_array;
@@ -115,16 +139,16 @@ void connections_append(connections_t *connections, SOCKET client, char *usernam
             printf("Failed to allocate memory for array\n");
         }
     }
-    connections->clients[connections->size].client = client;
+    connections->clients[connections->len].client = client;
-    connections->clients[connections->size].username = username;
+    connections->clients[connections->len].username = username;
-    connections->size = new_size;
+    connections->len = new_len;
     printf("{%llu} Connection added\n", connections->size);
     pthread_mutex_unlock(&mutex);
 
 
 };
 void connections_remove(connections_t *connections, SOCKET client) {
-    if (connections == NULL) {
+    if (connections == NULL || connections->clients == NULL) {
         exit(1);
     }
     pthread_mutex_lock(&mutex);
@@ -136,15 +160,20 @@ void connections_remove(connections_t *connections, SOCKET client) {
             for (int j = i; j < connections->size; j++) {
                 connections->clients[j] = connections->clients[j+1];
             }
-            connections->size--;
+            connections->len--;
             printf("{%llu} Connection removed\n", connections->size);
             pthread_mutex_unlock(&mutex);
             return;
         }
     }
+    pthread_mutex_unlock(&mutex);
+    printf("{%llu} Connection not found\n", connections->size);
 }
 
 void broadcast(const connections_t *connections, const SOCKET *source, const char *message) {
+    if (connections == NULL || connections->clients == NULL) {
+        exit(1);
+    }
     pthread_mutex_lock(&mutex);
     for (size_t i = 0; i < connections->size; i++) {
         if (connections->clients[i].client != *source) {

server03.h

@@ -24,10 +24,13 @@ typedef struct Connections {
 typedef struct handleArgs {
     int connection;
     SOCKET client;
-    connections_t connections;
+    connections_t *connections;
 } handle_args_t;
 
-
+typedef enum Status {
+    CONNECTED,
+    IDENTIFIED
+} status_t;
 
 void *handle_connection(void *args);
 

server03_chat_server_tests.py

@@ -2,6 +2,7 @@ import socket
 import threading
 import time
 import unittest
+import sys
 
 class TestBudgetChat(unittest.TestCase):
     SERVER_HOST = 'localhost'
@@ -39,9 +40,11 @@ class TestBudgetChat(unittest.TestCase):
                 _ = self.receive_message(client)  # Welcome message
                 client.send(f"{name}\n".encode('ascii'))
                 # Server should disconnect us
-                response = self.receive_message(client)
                 with self.assertRaises((ConnectionResetError, ConnectionAbortedError, socket.error)):
-                    client.send("test\n".encode('ascii'))
+                    client.sendall("test\n".encode('ascii'))
+                    response = self.receive_message(client)
+                    response = self.receive_message(client)
+                    response = self.receive_message(client)
                 client.close()
     
     def test_valid_username(self):
@@ -95,7 +98,7 @@ class TestBudgetChat(unittest.TestCase):
             client.send(f"{username}\n".encode('ascii'))
             _ = self.receive_message(client)  # Room info
             clients.append(client)
-            time.sleep(0.1)  # Small delay to prevent race conditions
+            # time.sleep(0.1)  # Small delay to prevent race conditions
         
         # Send a message from the last client
         test_message = "Hello from last user!"
@@ -105,6 +108,7 @@ class TestBudgetChat(unittest.TestCase):
         expected = f"[{usernames[-1]}] {test_message}"
         for i in range(len(clients)-1):
             received = self.receive_message(clients[i])
+            print(f"Received: {received}")
             self.assertEqual(expected, received)
         
         # Cleanup
@@ -126,10 +130,49 @@ class TestBudgetChat(unittest.TestCase):
         # Close client2 and check if client1 receives departure message
         client2.close()
         departure_msg = self.receive_message(client1)
+        print(departure_msg)
         self.assertTrue("user2" in departure_msg)
         self.assertTrue(departure_msg.startswith("*"))
         
         client1.close()
 
+def list_tests():
+    """List all available tests"""
+    print("\nAvailable tests:")
+    test_methods = [method for method in dir(TestBudgetChat) if method.startswith('test_')]
+    for i, test in enumerate(test_methods, 1):
+        print(f"{i}. {test}")
+    print("\n0. Run all tests")
+
+def run_selected_test(test_number):
+    """Run a specific test based on user selection"""
+    suite = unittest.TestSuite()
+    test_methods = [method for method in dir(TestBudgetChat) if method.startswith('test_')]
+    
+    if test_number == 0:
+        # Run all tests
+        suite.addTests(unittest.TestLoader().loadTestsFromTestCase(TestBudgetChat))
+    else:
+        try:
+            selected_test = test_methods[test_number - 1]
+            suite.addTest(TestBudgetChat(selected_test))
+        except IndexError:
+            print("Invalid test number!")
+            return
+
+    runner = unittest.TextTestRunner(verbosity=2)
+    runner.run(suite)
+
 if __name__ == '__main__':
-    unittest.main()
+    while True:
+        list_tests()
+        try:
+            choice = input("\nEnter test number (or 'q' to quit): ")
+            if choice.lower() == 'q':
+                break
+            test_number = int(choice)
+            run_selected_test(test_number)
+        except ValueError:
+            print("Please enter a valid number!")
+        
+        input("\nPress Enter to continue...")

server04.c

@@ -0,0 +1,137 @@
+//
+// Created by PeterDwyer on 30/07/2025.
+//
+
+#include "server04.h"
+#include <pthread.h>
+#include <winsock2.h>
+#include <stdio.h>
+#include "data.h"
+#include <stdbool.h>
+#include <inaddr.h>
+
+#define BUF_SIZE 1024
+
+int main() {
+    const SOCKET server = get_listen_socket_udp();
+    SOCKADDR_IN clientAddr;
+    SOCKET client;
+    int clientAddrSize = sizeof(clientAddr);
+    int connection_number = 1;
+    char *request = malloc(BUF_SIZE);
+    char buffer[BUF_SIZE] = {0};
+    data_map_t *data = data_map_create(1024);
+    printf("Listening for incoming connections...\n");
+    while (true) {
+        int bytesReceived = recvfrom(server, buffer, sizeof(buffer), 0, (SOCKADDR *) &clientAddr, &clientAddrSize);
+        const char *equals = "=";
+        size_t pos;
+        // IN_ADDR addr = clientAddr.sin_addr;
+        // printf("{%d} Client ip: |%d.%d.%d.%d| \n", connection_number, addr.S_un.S_un_b.s_b1, addr.S_un.S_un_b.s_b2, addr.S_un.S_un_b.s_b3, addr.S_un.S_un_b.s_b4);
+        // printf("{%d} Client port: |%d| \n", connection_number, clientAddr.sin_port);
+        printf("{%d} Client sent: |%s| \n", connection_number, buffer);
+        if ((pos = strcspn(buffer, equals)) != strlen(buffer)) {
+            key_value_t *kv = malloc(sizeof(key_value_t));
+            kv->key = malloc(sizeof(char)*1024);
+            kv->value = malloc(sizeof(char)*1024);
+            strncpy_s(kv->key, BUF_SIZE, buffer, pos);
+            strncpy_s(kv->value, BUF_SIZE, buffer + sizeof(char)*(pos+1), sizeof(buffer) - pos - 1);
+            data_map_insert_kv(data, kv);
+            printf("{%d} Key: |%s| Value: |%s| \n", connection_number, kv->key, kv->value);
+        } else {
+            printf("{%d} Client query: |%s| \n", connection_number, buffer);
+            char *value = data_map_get(data, buffer);
+            if (strcmp(buffer, "version") == 0) {
+                const char *version = "version=Ken's Key-Value Store 1.0";
+                sendto(server, version, strlen(version), 0, (SOCKADDR *) &clientAddr, clientAddrSize);
+            } else {
+                sprintf(buffer, "%s=%s", buffer, value);
+                sendto(server, buffer, strlen(buffer), 0, (SOCKADDR *) &clientAddr, clientAddrSize);
+            }
+
+        }
+        // sendto(server, buffer, bytesReceived, 0, (SOCKADDR *) &clientAddr, clientAddrSize);
+        // strncpy_s(request, BUF_SIZE, buffer, bytesReceived);
+        // printf("{%d} Client sent: |%s| \n", connection_number, request);
+        connection_number++;
+        memset(buffer, 0, sizeof(buffer));
+    }
+    data_map_free(data);
+    free(request);
+    return 0;
+}
+
+data_map_t *data_map_create(const int capacity) {
+    data_map_t *map = malloc(sizeof(data_map_t));
+    map->capacity = capacity;
+    map->count = 0;
+    map->data = calloc(capacity, sizeof(key_value_t));
+    return map;
+}
+void data_map_free(data_map_t *map) {
+    for (int i = 0; i < map->count; i++) {
+        free(map->data[i].key);
+        free(map->data[i].value);
+    }
+    free(map->data);
+    free(map);
+}
+void data_map_insert_kv(data_map_t *map, key_value_t *kv) {
+    if (map==NULL || map->data == NULL) {
+        exit(1);
+    }
+    for (int i = 0; i < map->count; i++) {
+        if (strcmp(map->data[i].key, kv->key) == 0) {
+            map->data[i].value = kv->value;
+            return;
+        }
+    }
+    const size_t new_size = map->count + 1;
+    if (new_size > map->capacity) {
+        map->capacity = map->capacity+1024;
+        key_value_t *new_array = realloc(map->data, map->capacity * sizeof(key_value_t));
+        map->data = new_array;
+    }
+    map->data[map->count] = *kv;
+    map->count = new_size;
+}
+
+void data_map_append(data_map_t *map, char *key, char *value) {
+    if (map->data == NULL) {
+        exit(1);
+    }
+    const size_t new_size = map->count + 1;
+    if (new_size > map->capacity) {
+        map->capacity = map->capacity+1024;
+        key_value_t *new_array = realloc(map->data, map->capacity * sizeof(key_value_t));
+        map->data = new_array;
+        if (map->data == NULL) {
+            printf("Failed to allocate memory for array\n");
+        }
+    }
+    map->data[map->count].key = key;
+    map->data[map->count].value = value;
+    map->count = new_size;
+}
+
+void data_map_insert(data_map_t *map, char *key, char *value) {
+    if (map->data == NULL) {
+        exit(1);
+    }
+    for (int i = 0; i < map->count; i++) {
+        if (strcmp(map->data[i].key, key) == 0) {
+            map->data[i].value = value;
+            return;
+        }
+    }
+    data_map_append(map, key, value);
+}
+
+char *data_map_get(const data_map_t *map, const char *key) {
+    for (int i = 0; i < map->count; i++) {
+        if (strcmp(map->data[i].key, key) == 0) {
+            return map->data[i].value;
+        }
+    }
+    return "";
+}

server04.h

@@ -0,0 +1,28 @@
+//
+// Created by PeterDwyer on 30/07/2025.
+//
+
+#ifndef SERVER04_H
+#define SERVER04_H
+#include <stddef.h>
+
+#endif //SERVER04_H
+
+typedef struct KeyValue {
+    char *key;
+    char *value;
+}key_value_t;
+
+typedef struct DataMap {
+    size_t capacity;
+    size_t count;
+    key_value_t *data;
+} data_map_t;
+
+
+data_map_t *data_map_create(int capacity);
+void data_map_free(data_map_t *map);
+void data_map_append(data_map_t *map, char *key, char *value);
+void data_map_insert(data_map_t *map, char *key, char *value);
+void data_map_insert_kv(data_map_t *map, key_value_t *kv);
+char *data_map_get(const data_map_t *map, const char *key);

server04_database_client_test_suite.py

@@ -0,0 +1,205 @@
+import socket
+import threading
+import time
+import random
+from typing import Optional, Dict, List, Tuple
+
+
+class DatabaseTestClient:
+    def __init__(self, host: str = 'localhost', server_port: int = 40000):
+        self.host = host
+        self.server_port = server_port
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM )
+        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        # Bind to any available interface (empty string) on an ephemeral port (0)
+        self.sock.bind(('0.0.0.0', 50000))
+        # Get the actual port assigned
+        self.client_port = self.sock.getsockname()[1]
+        self.sock.settimeout(5.0)  # 1 second timeout for receives
+        print(f"Client bound to port {self.client_port}")
+
+    def send_insert(self, key: str, value: str) -> None:
+        """Send an insert request."""
+        message = f"{key}={value}"
+        if len(message) >= 1000:
+            raise ValueError("Message too long")
+        self.sock.sendto(message.encode(), (self.host, self.server_port))
+
+    def send_retrieve(self, key: str) -> Optional[str]:
+        """Send a retrieve request and return the response."""
+        if len(key) >= 1000:
+            raise ValueError("Key too long")
+        self.sock.sendto(key.encode(), (self.host, self.server_port))
+        
+        try:
+            data, addr = self.sock.recvfrom(1024)  # Changed from recvmsg to recvfrom
+            return data.decode()
+        except socket.timeout:
+            return None
+
+    def close(self):
+        self.sock.close()
+
+def run_basic_tests(client: DatabaseTestClient) -> List[Tuple[str, bool, str]]:
+    """Run basic functionality tests."""
+    results = []
+    
+    # Test 1: Basic insert and retrieve
+    client.send_insert("test1", "value1")
+    time.sleep(0.1)  # Give server time to process
+    response = client.send_retrieve("test1")
+    results.append(("Basic insert/retrieve", 
+                   response == "test1=value1",
+                   f"Expected 'test1=value1', got '{response}'"))
+
+    # Test 2: Update existing key
+    client.send_insert("test1", "value2")
+    time.sleep(0.1)
+    response = client.send_retrieve("test1")
+    results.append(("Update existing key",
+                   response == "test1=value2",
+                   f"Expected 'test1=value2', got '{response}'"))
+
+    # Test 3: Empty key
+    client.send_insert("", "empty_key_value")
+    time.sleep(0.1)
+    response = client.send_retrieve("")
+    results.append(("Empty key",
+                   response == "=empty_key_value",
+                   f"Expected '=empty_key_value', got '{response}'"))
+
+    # Test 4: Empty value
+    client.send_insert("empty_value", "")
+    time.sleep(0.1)
+    response = client.send_retrieve("empty_value")
+    results.append(("Empty value",
+                   response == "empty_value=",
+                   f"Expected 'empty_value=', got '{response}'"))
+
+    # Test 5: Version check
+    response = client.send_retrieve("version")
+    results.append(("Version check",
+                   response is not None and response.startswith("version=") and len(response) > 8,
+                   f"Version response invalid: '{response}'"))
+
+    # Test 6: Version modification attempt
+    client.send_insert("version", "HACKED")
+    time.sleep(0.1)
+    response = client.send_retrieve("version")
+    results.append(("Version modification prevention",
+                   response is not None and not response.endswith("HACKED"),
+                   f"Version should not be modifiable, got: '{response}'"))
+
+    return results
+
+def run_edge_case_tests(client: DatabaseTestClient) -> List[Tuple[str, bool, str]]:
+    """Run edge case tests."""
+    results = []
+
+    # Test 1: Key with multiple equals signs
+    client.send_insert("multi=equals", "value=with=equals")
+    time.sleep(0.1)
+    response = client.send_retrieve("multi=equals")
+    results.append(("Multiple equals in key",
+                   response is None or not response.startswith("multi=equals"),
+                   "Key with equals sign should not be stored"))
+
+    # Test 2: Value with equals signs
+    client.send_insert("test2", "value=with=equals")
+    time.sleep(0.1)
+    response = client.send_retrieve("test2")
+    results.append(("Equals in value",
+                   response == "test2=value=with=equals",
+                   f"Expected 'test2=value=with=equals', got '{response}'"))
+
+    # Test 3: Non-existent key
+    response = client.send_retrieve("nonexistent")
+    results.append(("Non-existent key",
+                   response is None or response == "nonexistent=",
+                   f"Expected None or 'nonexistent=', got '{response}'"))
+
+    return results
+
+def run_concurrent_tests(num_clients: int = 5) -> List[Tuple[str, bool, str]]:
+    """Run concurrent access tests."""
+    results = []
+    clients = [DatabaseTestClient() for _ in range(num_clients)]
+    
+    def concurrent_ops(client_id: int):
+        client = clients[client_id]
+        key = f"concurrent_{client_id}"
+        for i in range(10):
+            value = f"value_{i}"
+            client.send_insert(key, value)
+            time.sleep(0.05)
+            response = client.send_retrieve(key)
+            if response != f"{key}={value}":
+                results.append((f"Concurrent client {client_id}",
+                              False,
+                              f"Expected '{key}={value}', got '{response}'"))
+                return
+        results.append((f"Concurrent client {client_id}",
+                       True,
+                       "All operations successful"))
+
+    threads = [threading.Thread(target=concurrent_ops, args=(i,))
+               for i in range(num_clients)]
+    
+    for thread in threads:
+        thread.start()
+    
+    for thread in threads:
+        thread.join()
+
+    for client in clients:
+        client.close()
+
+    return results
+
+def main():
+    # MESSAGE = "Hello, UDP!"
+    # sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP
+    # sock.sendto(bytes(MESSAGE, "utf-8"), ("localhost", 40000))
+    # quit()
+    # Allow command line arguments for host and port
+    import argparse
+    parser = argparse.ArgumentParser(description='Test UDP Database Server')
+    parser.add_argument('--host', default='localhost', help='Server host')
+    parser.add_argument('--port', type=int, default=40000, help='Server port')
+    args = parser.parse_args()
+
+    print(f"Starting Unusual Database Program Tests on {args.host}:{args.port}\n")
+
+    client = DatabaseTestClient(args.host, args.port)
+    # ... rest of the main function remains the same ...
+
+    print("Running basic functionality tests...")
+    basic_results = run_basic_tests(client)
+    
+    print("\nRunning edge case tests...")
+    edge_results = run_edge_case_tests(client)
+    
+    client.close()
+
+    print("\nRunning concurrent access tests...")
+    concurrent_results = run_concurrent_tests()
+
+    # Print results
+    all_results = basic_results + edge_results + concurrent_results
+    passed = sum(1 for _, success, _ in all_results if success)
+    total = len(all_results)
+
+    print("\nTest Results:")
+    print("=" * 60)
+    for test_name, success, message in all_results:
+        status = "✓" if success else "✗"
+        print(f"{status} {test_name}")
+        if not success:
+            print(f"   {message}")
+    
+    print("\nSummary:")
+    print(f"Passed: {passed}/{total} tests")
+    print(f"Success rate: {(passed/total)*100:.1f}%")
+
+if __name__ == "__main__":
+    main()

server05.c

@@ -0,0 +1,182 @@
+//
+// Created by Ajurna on 30/07/2025.
+//
+
+#include "server05.h"
+#include <pthread.h>
+#include <winsock2.h>
+#include <stdio.h>
+#include "data.h"
+#include <ctype.h>
+#include <stdint.h>
+#include <windows.h>
+#define PCRE2_CODE_UNIT_WIDTH 8
+#include <pcre2.h>
+
+
+const char *newline = "\n";
+const char *bogus_address = "7YWHMfk9JZe0LM0g1ZauHuiSxhI";
+
+int main() {
+    SOCKET server = get_listen_socket();
+    SOCKADDR_IN clientAddr;
+    SOCKET client;
+    int clientAddrSize = sizeof(clientAddr);
+    int connection_number = 1;
+
+    char *message = "Please pay the ticket price of 15 Boguscoins to one of these addresses: 7ABnYzozPt2cyDHQqDq2ExIMz53xXVcErn 7z6kM0VlNJpZiqTEHmRjxW9FbVCkv2flb 7qReHdk11Ai67nRvvfTQXFjPZH3X";
+    char *new_message = replace_bogus_coin(message);
+    // replace_bogus_coin(message);
+    printf("%s\n", new_message);
+    // exit(0);
+    printf("Listening for incoming connections...\n");
+    while((client = accept(server, (SOCKADDR *)&clientAddr, &clientAddrSize)) != INVALID_SOCKET)
+    {
+        handle_args_t *args = malloc(sizeof(handle_args_t));
+        args->client = client;
+        args->server = get_chat_socket();
+        args->connection = connection_number++;
+        pthread_t thread;
+        pthread_create(&thread, nullptr, handle_server, args);
+        pthread_create(&thread, nullptr, handle_client, args);
+    }
+    return 0;
+}
+
+void *handle_server(void *args) {
+    handle_args_t *handleArgs = args;
+    char buffer[1024] = {};
+    int bytesReceived;
+    printf("{%d} Server connected\n", handleArgs->connection);
+    char_array_t *data = char_array_create(1024);
+    while ((bytesReceived = recv(handleArgs->server, buffer, sizeof(buffer), 0)) > 0) {
+        printf("server sent {%d}: |%d| \n", handleArgs->connection, bytesReceived);
+        char_array_append(data, buffer, bytesReceived);
+        char *request;
+        while ((request = char_array_get_until_char(data, '\n')) != NULL) {
+            printf("{%d} server Said: %s\n", handleArgs->connection, request);
+            request = replace_bogus_coin(request);
+            send(handleArgs->client, request, strlen(request), 0);
+            send(handleArgs->client, newline, strlen(newline), 0);
+            free(request);
+        }
+        memset(buffer, 0, sizeof(buffer));
+    }
+    // closesocket(handleArgs->server);
+    return nullptr;
+}
+
+char *replace_bogus_coin(char *message) {
+    pcre2_code *re;
+    PCRE2_SPTR pattern = (PCRE2_SPTR)"\\b7\\w{25,34}\\b";
+    PCRE2_SPTR subject = (PCRE2_SPTR)message;
+    size_t subject_length = strlen((char *)subject);
+    int errornumber;
+    PCRE2_SIZE erroroffset;
+    PCRE2_SIZE *ovector;
+    int rc;
+    size_t offset = 0;  // Keep track of where we are in the string
+
+    // Compile the pattern
+    re = pcre2_compile(
+        pattern,
+        PCRE2_ZERO_TERMINATED,
+        0,
+        &errornumber,
+        &erroroffset,
+        NULL);
+
+    if (re == NULL) {
+        PCRE2_UCHAR buff[256];
+        pcre2_get_error_message(errornumber, buff, sizeof(buff));
+        printf("PCRE2 compilation failed at offset %d: %s\n", (int)erroroffset, buff);
+        return message;
+    }
+
+    // Create match data block
+    pcre2_match_data *match_data = pcre2_match_data_create_from_pattern(re, NULL);
+    char *result = strdup(message);  // Create a copy of the original message
+    
+    // Loop until no more matches are found
+    while (offset < subject_length) {
+        rc = pcre2_match(
+            re,
+            subject,
+            subject_length,
+            offset,     // Start from last match position
+            0,
+            match_data,
+            NULL);
+
+        if (rc < 0) {
+            break;  // No more matches
+        }
+
+        ovector = pcre2_get_ovector_pointer(match_data);
+        PCRE2_SIZE start = ovector[0];
+        PCRE2_SIZE end = ovector[1];
+        
+        // Replace the matched text with bogus_address
+        char *temp = calloc(strlen(result) + strlen(bogus_address) + 1, sizeof(char));
+        strncpy(temp, result, start);
+        strcat(temp, bogus_address);
+        strcat(temp, result + end);
+        
+        free(result);
+        result = temp;
+        
+        // Update the subject and length for next iteration
+        subject = (PCRE2_SPTR)result;
+        subject_length = strlen(result);
+        offset = start + strlen(bogus_address);
+    }
+
+    // Clean up
+    pcre2_match_data_free(match_data);
+    pcre2_code_free(re);
+
+    return result;
+}
+
+void *handle_client(void *args) {
+    handle_args_t *handleArgs = args;
+    char buffer[1024] = {};
+    int bytesReceived;
+    printf("{%d} Client connected\n", handleArgs->connection);
+    char_array_t *data = char_array_create(1024);
+    while ((bytesReceived = recv(handleArgs->client, buffer, sizeof(buffer), 0)) > 0) {
+        printf("server sent {%d}: |%d| \n", handleArgs->connection, bytesReceived);
+        char_array_append(data, buffer, bytesReceived);
+        char *request;
+
+        while ((request = char_array_get_until_char(data, '\n')) != NULL) {
+            printf("{%d} client Said: %s\n", handleArgs->connection, request);
+            request = replace_bogus_coin(request);
+            send(handleArgs->server, request, strlen(request), 0);
+            send(handleArgs->server, newline, strlen(newline), 0);
+            free(request);
+        }
+        memset(buffer, 0, sizeof(buffer));
+    }
+    // closesocket(handleArgs->client);
+    return nullptr;
+}
+
+
+
+SOCKET get_chat_socket() {
+    WSADATA WSAData;
+
+    SOCKADDR_IN serverAddr;
+    struct hostent * host = gethostbyname("chat.protohackers.com");
+    WSAStartup(MAKEWORD(2,0), &WSAData);
+    SOCKET server = socket(AF_INET, SOCK_STREAM, 0 );
+    serverAddr.sin_addr.s_addr = AF_INET;
+    serverAddr.sin_family = AF_INET;
+    memcpy(&serverAddr.sin_addr.s_addr, host->h_addr_list[0], host->h_length);
+
+    serverAddr.sin_port = htons(16963);
+
+    connect(server, (SOCKADDR *) & serverAddr, sizeof (serverAddr));
+    return server;
+}

server05.h

@@ -0,0 +1,31 @@
+//
+// Created by Ajurna on 30/07/2025.
+//
+
+#ifndef SERVER05_H
+#define SERVER05_H
+#include <winsock2.h>
+
+#endif //SERVER05_H
+
+typedef struct HandleArgs {
+    int connection;
+    SOCKET client;
+    SOCKET server;
+}handle_args_t;
+
+typedef struct BogusLocation {
+    size_t start;
+    size_t end;
+} bogus_location_t;
+
+typedef enum SearchState {
+    START,
+    END
+} search_state_t;
+
+void *handle_server(void *args);
+void *handle_client(void *args);
+void send_message(SOCKET dest, const char *message);
+char *replace_bogus_coin(char *message);
+SOCKET get_chat_socket();

server06.c

@@ -0,0 +1,43 @@
+//
+// Created by Ajurna on 01/08/2025.
+//
+
+#include "server06.h"
+#include <winsock2.h>
+#include <pthread.h>
+#include "data.h"
+#include <stdio.h>
+
+int main() {
+    SOCKET server = get_listen_socket();
+    SOCKADDR_IN clientAddr;
+    SOCKET client;
+    int clientAddrSize = sizeof(clientAddr);
+    int connection_number = 1;
+    printf("Listening for incoming connections...\n");
+    while((client = accept(server, (SOCKADDR *)&clientAddr, &clientAddrSize)) != INVALID_SOCKET)
+    {
+        handle_args_t *args = malloc(sizeof(handle_args_t));
+        args->client = client;
+        args->connection = connection_number++;
+        pthread_t thread;
+        pthread_create(&thread, nullptr, handle_connection, args);
+    }
+    return 0;
+}
+
+void *handle_connection(void *args) {
+    handle_args_t *handleArgs = args;
+    char buffer[1024] = {0};
+    int bytesReceived;
+    connection_type_t connection_type = UNKNOWN;
+    byte_array_t *data = byte_array_create(1024);
+    while ((bytesReceived = recv(handleArgs->client, buffer, sizeof(buffer), 0)) > 0) {
+        printf("Client sent {%d}: |%d| \n", handleArgs->connection, bytesReceived);
+        byte_array_append(data, buffer, bytesReceived);
+        char *request;
+        while ((request = byte_array_get_bytes(data, 1)) != NULL) {
+            parse_request(handleArgs, request, data);
+        }
+    }
+}

server06.h

@@ -0,0 +1,70 @@
+//
+// Created by Ajurna on 01/08/2025.
+//
+
+#ifndef SERVER06_H
+#define SERVER06_H
+#include <stdint.h>
+#include <winsock2.h>
+
+#endif //SERVER06_H
+
+typedef struct handleArgs {
+    int connection;
+    SOCKET client;
+}handle_args_t;
+
+typedef enum ConnectionType {
+    UNKNOWN,
+    CAMERA,
+    DISPATCHER,
+} connection_type_t;
+
+typedef enum MessageType {
+    ERROR_MSG = 0x10,
+    PLATE_MSG = 0x20,
+    TICKET_MSG = 0x21,
+    WANT_HEARTBEAT_MSG = 0x40,
+    HEARTBEAT_MSG = 0x41,
+    I_AM_CAMERA_MSG = 0x80,
+    I_AM_DISPATCHER_MSG = 0x81,
+}message_type_t;
+
+typedef struct ErrorMsg {
+    char *message;
+} error_msg_t;
+
+typedef struct PlateMsg {
+    char *plate;
+    uint32_t timestamp;
+} plate_msg_t;
+
+typedef struct TicketMsg {
+    char *plate;
+    uint16_t road;
+    uint16_t mile1;
+    uint32_t timestamp1;
+    uint16_t mile2;
+    uint32_t timestamp2;
+    uint16_t speed;
+} ticket_msg_t;
+
+typedef struct WantHeartbeatMsg {
+    uint32_t timestamp;
+} want_heartbeat_msg_t;
+
+typedef struct HeartbeatMsg {
+
+} heartbeat_msg_t;
+
+typedef struct IAmCameraMsg {
+    uint16_t road;
+    uint16_t mile;
+    uint16_t limit;
+} i_am_camera_msg_t;
+
+typedef struct IAmDispatcherMsg {
+    uint16_t *road;
+} i_am_dispatcher_msg_t;
+
+void *handle_connection(void *args);

speed_ticket_monitoring_system.py

@@ -0,0 +1,141 @@
+import socket
+import struct
+import time
+from threading import Thread
+from typing import List, Optional
+
+class MessageType:
+    ERROR = 0x10
+    PLATE = 0x20
+    TICKET = 0x21
+    WANT_HEARTBEAT = 0x40
+    HEARTBEAT = 0x41
+    I_AM_CAMERA = 0x80
+    I_AM_DISPATCHER = 0x81
+
+class SpeedDaemonClient:
+    def __init__(self, host: str = 'localhost', port: int = 12345):
+        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.socket.connect((host, port))
+        self.running = True
+        self.received_tickets = []
+        
+    def send_bytes(self, data: bytes):
+        self.socket.send(data)
+        
+    def receive_message(self) -> Optional[tuple]:
+        try:
+            msg_type = self.socket.recv(1)
+            if not msg_type:
+                return None
+                
+            msg_type = msg_type[0]
+            
+            if msg_type == MessageType.ERROR:
+                length = struct.unpack('!B', self.socket.recv(1))[0]
+                message = self.socket.recv(length).decode('ascii')
+                return (MessageType.ERROR, message)
+                
+            elif msg_type == MessageType.TICKET:
+                # Read plate length
+                plate_len = struct.unpack('!B', self.socket.recv(1))[0]
+                plate = self.socket.recv(plate_len).decode('ascii')
+                
+                # Read other fields
+                data = self.socket.recv(16)
+                road, mile1, timestamp1, mile2, timestamp2, speed = struct.unpack('!HHIHHI', data)
+                return (MessageType.TICKET, {
+                    'plate': plate,
+                    'road': road,
+                    'mile1': mile1,
+                    'timestamp1': timestamp1,
+                    'mile2': mile2,
+                    'timestamp2': timestamp2,
+                    'speed': speed
+                })
+                
+            elif msg_type == MessageType.HEARTBEAT:
+                return (MessageType.HEARTBEAT, None)
+                
+        except Exception as e:
+            print(f"Error receiving message: {e}")
+            return None
+            
+    def close(self):
+        self.running = False
+        self.socket.close()
+
+class Camera(SpeedDaemonClient):
+    def __init__(self, road: int, mile: int, limit: int, host: str = 'localhost', port: int = 12345):
+        super().__init__(host, port)
+        self.road = road
+        self.mile = mile
+        self.limit = limit
+        self.register()
+        
+    def register(self):
+        # Send IAmCamera message
+        msg = struct.pack('!BHHH', MessageType.I_AM_CAMERA, self.road, self.mile, self.limit)
+        self.send_bytes(msg)
+        
+    def report_plate(self, plate: str, timestamp: int):
+        # Send Plate message
+        msg = struct.pack(f'!BB{len(plate)}sI', MessageType.PLATE, len(plate), 
+                         plate.encode('ascii'), timestamp)
+        self.send_bytes(msg)
+
+class Dispatcher(SpeedDaemonClient):
+    def __init__(self, roads: List[int], host: str = 'localhost', port: int = 12345):
+        super().__init__(host, port)
+        self.roads = roads
+        self.register()
+        # Start listening for tickets
+        self.listener_thread = Thread(target=self._listen_for_tickets)
+        self.listener_thread.start()
+        
+    def register(self):
+        # Send IAmDispatcher message
+        roads_data = struct.pack(f'!{len(self.roads)}H', *self.roads)
+        msg = struct.pack('!BB', MessageType.I_AM_DISPATCHER, len(self.roads)) + roads_data
+        self.send_bytes(msg)
+        
+    def _listen_for_tickets(self):
+        while self.running:
+            message = self.receive_message()
+            if message and message[0] == MessageType.TICKET:
+                self.received_tickets.append(message[1])
+
+def run_speed_test():
+    # Create a dispatcher for road 123
+    dispatcher = Dispatcher([123])
+    time.sleep(0.1)  # Give dispatcher time to register
+    
+    # Create two cameras on road 123
+    camera1 = Camera(123, 8, 60)  # Camera at mile 8, 60mph limit
+    camera2 = Camera(123, 9, 60)  # Camera at mile 9, same limit
+    time.sleep(0.1)  # Give cameras time to register
+    
+    # Report a speeding car (same as in example session)
+    camera1.report_plate("UN1X", 0)
+    camera2.report_plate("UN1X", 45)  # 1 mile in 45 seconds = 80mph
+    
+    # Wait for ticket processing
+    time.sleep(1)
+    
+    # Check received tickets
+    if dispatcher.received_tickets:
+        print("Test passed! Received tickets:")
+        for ticket in dispatcher.received_tickets:
+            print(f"Plate: {ticket['plate']}")
+            print(f"Road: {ticket['road']}")
+            print(f"Speed: {ticket['speed']/100.0} mph")
+    else:
+        print("Test failed: No tickets received")
+    
+    # Cleanup
+    dispatcher.close()
+    camera1.close()
+    camera2.close()
+
+if __name__ == "__main__":
+    run_speed_test()