编写一个基于C/S结构的C语言程序，客户端和服务器可建立基于TCP的连接，客户端可持续向服务器发送信息

在C语言中，编写一个基于Client-Server（C/S）结构并且通过TCP通信的应用通常涉及使用socket编程。以下是简化的示例，展示如何创建一个基本的TCP客户端和服务器：

**服务器端（server.c）**:

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

#define PORT 8080

int main() {
    int server_socket, client_socket;
    struct sockaddr_in server_addr, client_addr;
    socklen_t addr_len = sizeof(struct sockaddr_in);

    // 创建套接字并绑定
    if ((server_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("Failed to create socket");
        exit(EXIT_FAILURE);
    }
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(server_socket, (struct sockaddr *)&server_addr, addr_len) == -1) {
        perror("Failed to bind socket");
        close(server_socket);
        exit(EXIT_FAILURE);
    }

    // 监听
    listen(server_socket, 5);

    printf("Server listening on port %d...\n", PORT);

    while (true) {
        // 接受客户端连接
        if ((client_socket = accept(server_socket, (struct sockaddr *)&client_addr, &addr_len)) == -1) {
            perror("Failed to accept connection");
            continue;
        }

        char buffer[100];
        read(client_socket, buffer, sizeof(buffer));

        printf("Received message from client: %s\n", buffer);

        write(client_socket, "Message received!", strlen("Message received!"));
        close(client_socket);
    }

    return 0;
}

**客户端（client.c）**:

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

#define SERVER_IP "localhost"
#define PORT 8080

int main() {
    int client_socket;
    struct sockaddr_in server_addr;
    char message[] = "Hello Server!";

    if ((client_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("Failed to create socket");
        exit(EXIT_FAILURE);
    }

    server_addr.sin_family = AF_INET;
    inet_pton(AF_INET, SERVER_IP, &server_addr.sin_addr);
    server_addr.sin_port = htons(PORT);

    if (connect(client_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("Failed to connect to server");
        close(client_socket);
        exit(EXIT_FAILURE);
    }

    write(client_socket, message, strlen(message));
    printf("Message sent to the server.\n");

    char response[100];
    read(client_socket, response, sizeof(response));

    printf("Server's response: %s\n", response);
    close(client_socket);

    return 0;
}

这个例子中，服务器监听指定端口，接受客户端连接，读取消息并回应。客户端创建套接字，连接到服务器，发送消息，并接收响应。