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