1. #include <stdio.h>
2. #include <stdlib.h>
3. #include <string.h>
4. #include <winsock2.h>
5. #include <windows.h>
6. #include <pthread.h>
7.  
8. #define PORT 12345
9. #define BUFFER_SIZE 1024
10. #define MAX_CLIENTS 5
11.  
12. // Structure to hold client information
13. struct ClientInfo {
14.     SOCKET socket;
15.     struct sockaddr_in address;
16. };
17.  
18. // Function to handle each client
19. DWORD WINAPI handleClient(LPVOID lpParam) {
20.     struct ClientInfo *clientInfo = (struct ClientInfo *)lpParam;
21.     SOCKET clientSocket = clientInfo->socket;
22.  
23.     // Open and send file
24.     FILE *fileToSend = fopen&#40;"file_to_send.txt", "rb"&#41;;
25.     if (!fileToSend) {
26.         printf("Error opening file\n");
27.         closesocket(clientSocket);
28.         free(clientInfo);
29.         return 1;
30.     }
31.  
32.     char buffer[BUFFER_SIZE];
33.  
34.     while (1) {
35.         int bytesRead = fread(buffer, 1, sizeof(buffer), fileToSend);
36.         if (bytesRead <= 0) {
37.             break; // End of file or error
38.         }
39.         send(clientSocket, buffer, bytesRead, 0);
40.     }
41.  
42.     printf("File sent to %s:%d\n", inet_ntoa(clientInfo->address.sin_addr), ntohs(clientInfo->address.sin_port));
43.  
44.     // Close the socket and file
45.     fclose(fileToSend);
46.     closesocket(clientSocket);
47.     free(clientInfo);
48.     return 0;
49. }
50.  
51. int main() {
52.     WSADATA wsaData;
53.     SOCKET serverSocket, clientSocket;
54.     struct sockaddr_in serverAddr, clientAddr;
55.     int addrSize = sizeof(struct sockaddr_in);
56.  
57.     // Initialize Winsock
58.     if (WSAStartup(MAKEWORD(2, 2), &wsaData;) != 0) {
59.         printf("WSAStartup failed\n");
60.         return 1;
61.     }
62.  
63.     // Create socket
64.     if ((serverSocket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
65.         printf("Error creating socket: %d\n", WSAGetLastError());
66.         WSACleanup();
67.         return 1;
68.     }
69.  
70.     // Configure server address
71.     memset(&serverAddr;, 0, sizeof(serverAddr));
72.     serverAddr.sin_family = AF_INET;
73.     serverAddr.sin_port = htons(PORT);
74.     serverAddr.sin_addr.s_addr = INADDR_ANY;
75.  
76.     // Bind the socket
77.     if (bind(serverSocket, (struct sockaddr *)&serverAddr;, sizeof(serverAddr)) == SOCKET_ERROR) {
78.         printf("Error binding socket: %d\n", WSAGetLastError());
79.         closesocket(serverSocket);
80.         WSACleanup();
81.         return 1;
82.     }
83.  
84.     // Listen for incoming connections
85.     if (listen(serverSocket, MAX_CLIENTS) == SOCKET_ERROR) {
86.         printf("Error listening for connections: %d\n", WSAGetLastError());
87.         closesocket(serverSocket);
88.         WSACleanup();
89.         return 1;
90.     }
91.  
92.     printf("Server listening on port %d...\n", PORT);
93.  
94.     while (1) {
95.         // Accept a connection
96.         if ((clientSocket = accept(serverSocket, (struct sockaddr *)&clientAddr;, &addrSize;)) == INVALID_SOCKET) {
97.             printf("Error accepting connection: %d\n", WSAGetLastError());
98.             closesocket(serverSocket);
99.             WSACleanup();
100.             return 1;
101.         }
102.  
103.         // Create a new thread to handle the client
104.         struct ClientInfo *clientInfo = (struct ClientInfo *)malloc(sizeof(struct ClientInfo));
105.         clientInfo->socket = clientSocket;
106.         clientInfo->address = clientAddr;
107.  
108.         HANDLE hThread = CreateThread(NULL, 0, handleClient, (LPVOID)clientInfo, 0, NULL);
109.         if (hThread == NULL) {
110.             printf("Error creating thread\n");
111.             closesocket(clientSocket);
112.             free(clientInfo);
113.         } else {
114.             CloseHandle(hThread);
115.         }
116.     }
117.  
118.     // Close the server socket
119.     closesocket(serverSocket);
120.     WSACleanup();
121.  
122.     return 0;
123. }
124.