在Windows环境下编写具体的C语言代码实现远程log保存、查询功能 1、实现一个tcp server端 2、实现一个tcp client端 3、server端和client自己设计简单的协议(如read_log write_log get_res 等等) 4、log保存在server端 5、client 通过socket向server端发送请求 写一条log/读所有log/计算数据采集结果 6、server通过socket返回响应Client查询结果 7、当client异常退出时，server端应该有对应的处理机制（自行设计处理机制） 8、server端的log打印不做任何要求，但是client正常/异常离线需要有对应的log，请编写出具体的代码给我

以下是一个简单的C语言代码实现远程log保存、查询功能的示例：

server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>

#define PORT 8888
#define BUF_SIZE 1024
#define LOG_FILE "log.txt"

struct client_info {
    SOCKET socket;
    int is_online;
};

void save_log(const char *log) {
    FILE *fp = fopen(LOG_FILE, "a");
    if (fp == NULL) {
        printf("Failed to open log file\n");
        return;
    }
    fprintf(fp, "%s\n", log);
    fclose(fp);
}

void handle_request(SOCKET socket, const char *buf, struct client_info *clients, int num_clients) {
    char response[BUF_SIZE];
    char cmd[BUF_SIZE], arg[BUF_SIZE];
    int i, online_clients = 0;

    sscanf(buf, "%s %s", cmd, arg);

    if (strcmp(cmd, "write_log") == 0) {
        save_log(arg);
        sprintf(response, "OK");
    } else if (strcmp(cmd, "read_log") == 0) {
        FILE *fp = fopen(LOG_FILE, "r");
        if (fp == NULL) {
            sprintf(response, "Failed to open log file");
        } else {
            response[0] = '\0';
            while (fgets(buf, BUF_SIZE, fp) != NULL) {
                strcat(response, buf);
            }
            fclose(fp);
        }
    } else if (strcmp(cmd, "get_res") == 0) {
        for (i = 0; i < num_clients; i++) {
            if (clients[i].is_online) {
                online_clients++;
            }
        }
        sprintf(response, "Online clients: %d", online_clients);
    } else {
        sprintf(response, "Invalid command");
    }

    send(socket, response, strlen(response), 0);
}

void handle_client(SOCKET socket, struct client_info *clients, int num_clients) {
    char buf[BUF_SIZE];
    int nbytes, i, client_index = -1;

    for (i = 0; i < num_clients; i++) {
        if (clients[i].socket == INVALID_SOCKET) {
            client_index = i;
            break;
        }
    }

    if (client_index == -1) {
        printf("Too many clients, closing connection\n");
        closesocket(socket);
        return;
    }

    clients[client_index].socket = socket;
    clients[client_index].is_online = 1;

    printf("Client connected\n");

    while ((nbytes = recv(socket, buf, BUF_SIZE, 0)) > 0) {
        buf[nbytes] = '\0';
        printf("Received: %s\n", buf);
        handle_request(socket, buf, clients, num_clients);
    }

    printf("Client disconnected\n");

    closesocket(socket);
    clients[client_index].socket = INVALID_SOCKET;
    clients[client_index].is_online = 0;
}

int main() {
    WSADATA wsa;
    SOCKET listen_socket, client_socket;
    struct sockaddr_in server_addr, client_addr;
    int addr_len = sizeof(client_addr);
    struct client_info clients[10];
    int i;

    for (i = 0; i < 10; i++) {
        clients[i].socket = INVALID_SOCKET;
        clients[i].is_online = 0;
    }

    if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0) {
        printf("Failed to initialize Winsock\n");
        return 1;
    }

    if ((listen_socket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
        printf("Failed to create socket\n");
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);

    if (bind(listen_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) == SOCKET_ERROR) {
        printf("Failed to bind socket\n");
        return 1;
    }

    if (listen(listen_socket, 10) == SOCKET_ERROR) {
        printf("Failed to listen on socket\n");
        return 1;
    }

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

    while (1) {
        if ((client_socket = accept(listen_socket, (struct sockaddr *)&client_addr, &addr_len)) == INVALID_SOCKET) {
            printf("Failed to accept connection\n");
            continue;
        }
        handle_client(client_socket, clients, 10);
    }

    closesocket(listen_socket);
    WSACleanup();

    return 0;
}

client.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>

#define SERVER_ADDR "127.0.0.1"
#define PORT 8888
#define BUF_SIZE 1024

int send_request(SOCKET socket, const char *buf) {
    int nbytes = send(socket, buf, strlen(buf), 0);
    if (nbytes == SOCKET_ERROR) {
        printf("Failed to send request\n");
        return 0;
    }
    return 1;
}

int main() {
    WSADATA wsa;
    SOCKET socket;
    struct sockaddr_in server_addr;
    char buf[BUF_SIZE];

    if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0) {
        printf("Failed to initialize Winsock\n");
        return 1;
    }

    if ((socket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
        printf("Failed to create socket\n");
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr(SERVER_ADDR);
    server_addr.sin_port = htons(PORT);

    if (connect(socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) == SOCKET_ERROR) {
        printf("Failed to connect to server\n");
        return 1;
    }

    printf("Connected to server\n");

    while (1) {
        printf("> ");
        fgets(buf, BUF_SIZE, stdin);
        if (buf[strlen(buf) - 1] == '\n') {
            buf[strlen(buf) - 1] = '\0';
        }
        if (strcmp(buf, "quit") == 0) {
            break;
        }
        if (!send_request(socket, buf)) {
            continue;
        }
        if (recv(socket, buf, BUF_SIZE, 0) > 0) {
            buf[strlen(buf)] = '\0';
            printf("Response: %s\n", buf);
        } else {
            printf("Failed to receive response\n");
        }
    }

    closesocket(socket);
    WSACleanup();

    return 0;
}

启动server后，可以使用client向server发送请求，如：

write_log test log message
read_log
get_res

server会对请求进行处理，并返回相应的响应。