C 语言实现基于 SQLite 的智能家居设备状态监测服务器

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <arpa/inet.h> #include <sqlite3.h> #include <pthread.h> #include <signal.h>

#define MAX_BUFFER_SIZE 1024

// 设备状态结构体 typedef struct { int uid; char device_name[10]; char device_state[10]; char value[10]; char mode[10]; } Status;

// 服务器上下文结构体，包含服务器相关信息 typedef struct { int sockfd; struct sockaddr_in client_addr; socklen_t client_addr_len; sqlite3 *db; pthread_mutex_t mutex; int running; } ServerContext;

// 处理客户端请求 void handleClientRequest(ServerContext *context) { char buffer[MAX_BUFFER_SIZE]; int userid;

// 接收客户端发送的userid
ssize_t recvSize = recv(context->sockfd, &userid, sizeof(int), 0);
if (recvSize == -1) {
    perror("recv");
    return;
}

// 查询数据库获取设备状态信息
char sql[100];
snprintf(sql, sizeof(sql), "SELECT * FROM Status WHERE uid = %d", userid);
sqlite3_stmt *stmt;
int rc = sqlite3_prepare_v2(context->db, sql, -1, &stmt, NULL);
if (rc != SQLITE_OK) {
    fprintf(stderr, "Failed to execute statement: %s\n", sqlite3_errmsg(context->db));
    return;
}

Status status;
rc = sqlite3_step(stmt);
if (rc == SQLITE_ROW) {
    status.uid = sqlite3_column_int(stmt, 1);
    strncpy(status.device_name, sqlite3_column_text(stmt, 2), sizeof(status.device_name)-1);
    strncpy(status.device_state, sqlite3_column_text(stmt, 3), sizeof(status.device_state)-1);
    strncpy(status.value, sqlite3_column_text(stmt, 4), sizeof(status.value)-1);
    strncpy(status.mode, sqlite3_column_text(stmt, 5), sizeof(status.mode)-1);
} else if (rc == SQLITE_DONE) {
    fprintf(stderr, "No data found for user %d\n", userid);
    sqlite3_finalize(stmt);
    return;
} else {
    fprintf(stderr, "Failed to execute statement: %s\n", sqlite3_errmsg(context->db));
    sqlite3_finalize(stmt);
    return;
}
sqlite3_finalize(stmt);

// 分析设备状态并生成建议
char suggestion[MAX_BUFFER_SIZE];
if (strcmp(status.device_name, "空调") == 0) {
    int temperature = atoi(status.value);
    if (temperature < 24) {
        snprintf(suggestion, sizeof(suggestion), "空调温度过低，建议提高温度至26℃");
    } else {
        snprintf(suggestion, sizeof(suggestion), "空调温度正常");
    }
} else if (strcmp(status.device_name, "加湿器") == 0) {
    int humidity = atoi(status.value);
    if (humidity < 40 || humidity > 70) {
        snprintf(suggestion, sizeof(suggestion), "加湿器湿度过高或过低，建议调整加湿器湿度");
    } else {
        snprintf(suggestion, sizeof(suggestion), "加湿器湿度正常");
    }
} else {
    snprintf(suggestion, sizeof(suggestion), "设备状态未知");
}

// 向客户端发送建议
ssize_t sendSize = send(context->sockfd, suggestion, strlen(suggestion), 0);
if (sendSize == -1) {
    perror("send");
    return;
}

}

// 处理客户端连接 void *handleClientConnection(void *arg) { ServerContext *context = (ServerContext *)arg; int clientSockfd = accept(context->sockfd, (struct sockaddr *)&context->client_addr, &context->client_addr_len); if (clientSockfd == -1) { perror("accept"); return NULL; }

context->sockfd = clientSockfd;
handleClientRequest(context);

close(clientSockfd);
return NULL;

}

// 信号处理函数，修改running的值 void handleSignal(int sig) { if (sig == SIGINT) { context->running = 0; } }

int main() { // 创建套接字 int sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd == -1) { perror("socket"); return 1; }

// 设置服务器地址
struct sockaddr_in server_addr;
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
server_addr.sin_port = htons(12345);

// 绑定套接字到服务器地址
if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
    perror("bind");
    close(sockfd);
    return 1;
}

// 监听连接请求
if (listen(sockfd, 5) == -1) {
    perror("listen");
    close(sockfd);
    return 1;
}

// 打开数据库
sqlite3 *db;
int rc = sqlite3_open("database.db", &db);
if (rc != SQLITE_OK) {
    fprintf(stderr, "Failed to open database: %s\n", sqlite3_errmsg(db));
    close(sockfd);
    return 1;
}

// 初始化服务器上下文
ServerContext context;
context.sockfd = sockfd;
context.client_addr_len = sizeof(context.client_addr);
context.db = db;
pthread_mutex_init(&context.mutex, NULL);
context.running = 1;

// 注册信号处理函数
signal(SIGINT, handleSignal);

// 循环处理客户端连接
while (context.running) {
    pthread_t tid;
    int err = pthread_create(&tid, NULL, handleClientConnection, &context);
    if (err != 0) {
        fprintf(stderr, "Failed to create thread: %d\n", err);
        break;
    }
    err = pthread_detach(tid);
    if (err != 0) {
        fprintf(stderr, "Failed to detach thread: %d\n", err);
        break;
    }
}

// 关闭数据库
rc = sqlite3_close(db);
if (rc != SQLITE_OK) {
    fprintf(stderr, "Failed to close database: %s\n", sqlite3_errmsg(db));
    return 1;
}

// 关闭套接字
if (close(sockfd) == -1) {
    perror("close");
    return 1;
}

pthread_mutex_destroy(&context.mutex);
return 0;

}