c++ 保存txt文件

#include <iostream>
#include <stdio.h>
#include <fstream>
#include <queue>
#include <mutex>


    std::string gpssavename="/home/dongdong/v2_Project/v3_SLAM/v5_VinsFusion/catkin/src/VINS-Fusion/outdata/vio_global.csv";
    std::ofstream foutC(gpssavename, ios::app);
    foutC.setf(ios::fixed, ios::floatfield);
    foutC.precision(0);
    foutC << pose_msg->header.stamp.toSec() << " ";
    foutC.precision(5);
    foutC   << global_t.x() << " "
            << global_t.y() << " "
            << global_t.z() << " "
            << global_q.w() << " "
            << global_q.x() << " "
            << global_q.y() << " "
            << global_q.z() << endl;
    foutC.close();