c++ file open/write test android

gistfile1.txt

      ALOGV(TAG, "#####################################################################");
        std::fstream f;
        ALOGV(TAG, "original filePath: %s", filePath.c_str());
        std::string filePath2 = "/storage/emulated/0/Android/data/com.stompai.flutter_app/files/something_3.txt";//filePath + "22w";
        ALOGV(TAG, "gonna open filePath2: %s", filePath2.c_str());
        f.open(filePath2, std::ios_base::binary | std::ios_base::in | std::ios_base::out);
        if (f.is_open()) {
            ALOGV(TAG, "is open");
        } else {
            ALOGV(TAG, "is closed");
        }
        //Write some data to vector
        std::vector<char> v;
        v.push_back(1);
        v.push_back(2);
        v.push_back(3);
        v.push_back(4);
        v.push_back(5);
        //Go to beggining of the file to write
        f.seekg(0, std::ios::beg);
        f.seekp(0, std::ios::beg);
        //Write the vector to file
        f.write(v.data(), v.size());
        f.flush();
        //Lets read so we see that things were written to the file
        ALOGV(TAG, "seeking g and p to beggining");
        //Don't know why I've put clear, but won't work without it too
        //f.clear();
        f.seekg(0, std::ios::beg);
        f.seekp(0, std::ios::beg);
        auto v2 = std::vector<char>(v.size());
        //Read things back to file
        f.read(v2.data(), v2.size());
        if (f) {
            ALOGV(TAG, "did read everything");
        } else {
            ALOGV(TAG, "did read only : %d", f.gcount());
        }
        auto* b1 = v2.data();
        for (int i=0; i<v2.size(); i++) {
            ALOGV(TAG, "b1[%d] = %d", i, b1[i]);
        }
        f.close();
        //Lets open again to see if modifications were recorded permanently
        ALOGV(TAG, "gonna open filePath2: %s", filePath2.c_str());
        f.open(filePath2, std::ios_base::binary | std::ios_base::in | std::ios_base::out);
        if (f.is_open()) {
            ALOGV(TAG, "is open");
        } else {
            ALOGV(TAG, "is closed");
        }
        ALOGV(TAG, "seeking g and p to beggining");
        f.clear();
        f.seekg(0, std::ios::beg);
        f.seekp(0, std::ios::beg);
        std::vector<char> v3(v.size());
        f.read(v3.data(), v3.size());
        if (f) {
            ALOGV(TAG, "did read everything");
        } else {
            ALOGV(TAG, "did read only : %d", f.gcount());
        }
        auto* b3 = v3.data();
        for (int i=0; i<v3.size(); i++) {
            ALOGV(TAG, "b3[%d] = %d", i, b3[i]);
        }
        f.close();
        ALOGV(TAG, "$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");