TCP Server

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>

int socket_desc, client_sock;

void close_socket(void) {
    if (socket_desc >= 0) close(socket_desc);
    if (client_sock >= 0) close(client_sock);
}

int main(void) {
    struct sockaddr_in server_addr, client_addr;
    char server_message[2000], client_message[2000];

    // Register cleanup function
    atexit(close_socket);

    // Initialize socket descriptors
    socket_desc = -1;
    client_sock = -1;

    // Clean buffers:
    memset(server_message, 0, sizeof(server_message));
    memset(client_message, 0, sizeof(client_message));

    // Create socket:
    socket_desc = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_desc < 0) {
        perror("Error while creating socket");
        exit(EXIT_FAILURE);
    }
    printf("Socket created successfully\n");

    // Set port and IP:
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(2000);
    server_addr.sin_addr.s_addr = INADDR_ANY;  // Accept connections on any IP

    // Bind to the set port and IP:
    if (bind(socket_desc, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("Couldn't bind to the port");
        exit(EXIT_FAILURE);
    }
    printf("Binding successful\n");

    // Listen for clients:
    if (listen(socket_desc, 1) < 0) {
        perror("Error while listening");
        exit(EXIT_FAILURE);
    }
    printf("Listening for incoming connections...\n");

    // Accept an incoming connection:
    socklen_t client_size = sizeof(client_addr);
    client_sock = accept(socket_desc, (struct sockaddr*)&client_addr, &client_size);

    if (client_sock < 0) {
        perror("Can't accept");
        exit(EXIT_FAILURE);
    }
    printf("Client connected at IP: %s and port: %i\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

    // Receive client's message:
    ssize_t recv_size = recv(client_sock, client_message, sizeof(client_message) - 1, 0);
    if (recv_size < 0) {
        perror("Couldn't receive");
        exit(EXIT_FAILURE);
    }
    client_message[recv_size] = '\0';  // Ensure null-termination
    printf("Msg from client: %s\n", client_message);

    // Respond to client:
    strcpy(server_message, "This is the server's message.");

    if (send(client_sock, server_message, strlen(server_message), 0) < 0) {
        perror("Can't send");
        exit(EXIT_FAILURE);
    }

    return 0;
}