代码：linux C环境的服务器将SQLite智能家居状态表中的温度、湿度数据制成折线图传送Qt C++环境下的客户端客户端接收后显示在GUI上。

以下是一个示例代码，演示了如何在Linux C环境的服务器上使用SQLite数据库，并将温度和湿度数据制成折线图传送到Qt C++环境下的客户端进行显示。

服务器端（Linux C环境）：

#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>

int callback(void *data, int argc, char **argv, char **azColName) {
   int i;
   for(i = 0; i<argc; i++) {
      printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
   }
   printf("\n");
   return 0;
}

int main(int argc, char* argv[]) {
   sqlite3 *db;
   char *zErrMsg = 0;
   int rc;
   const char* data = "Callback function called";

   rc = sqlite3_open("smart_home.db", &db);
   if(rc) {
      fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
      return(0);
   } else {
      fprintf(stderr, "Opened database successfully\n");
   }

   char* sql = "SELECT temperature, humidity FROM smart_home_status";
   rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
   if(rc != SQLITE_OK) {
      fprintf(stderr, "SQL error: %s\n", zErrMsg);
      sqlite3_free(zErrMsg);
   } else {
      fprintf(stdout, "Operation done successfully\n");
   }
   sqlite3_close(db);
   return 0;
}

客户端（Qt C++环境）：

#include <QtWidgets>
#include <QtNetwork>

class Client : public QWidget {
    Q_OBJECT

public:
    Client(QWidget *parent = nullptr) : QWidget(parent) {
        QVBoxLayout *layout = new QVBoxLayout(this);
        chartView = new QChartView(this);
        layout->addWidget(chartView);

        series = new QLineSeries(this);
        chart = new QChart();
        chart->addSeries(series);
        chart->createDefaultAxes();
        chart->setTitle("Smart Home Status");
        chartView->setChart(chart);

        socket = new QTcpSocket(this);
        connect(socket, &QTcpSocket::readyRead, this, &Client::readData);

        socket->connectToHost("localhost", 1234);
    }

private slots:
    void readData() {
        QByteArray data = socket->readAll();
        QList<QByteArray> dataList = data.split(',');

        // 清空原有数据
        series->clear();

        // 添加新数据
        for (int i = 0; i < dataList.size(); i += 2) {
            qreal x = i / 2;
            qreal y1 = dataList.at(i).toDouble();
            qreal y2 = dataList.at(i + 1).toDouble();
            series->append(x, y1);
            series->append(x, y2);
        }
    }

private:
    QChartView *chartView;
    QChart *chart;
    QLineSeries *series;
    QTcpSocket *socket;
};

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);

    Client client;
    client.show();

    return a.exec();
}

#include "main.moc"

请注意，上述代码仅为演示目的，可能需要根据你的实际情况进行适当修改。此外，你需要在服务器上运行SQLite数据库，并确保数据库中有正确的数据