Google unit testing in C++: how to write a persistent data file?

Question

Questions:

1) Where do files go that are created by a C++ Google unit test?

2) Is there a way to write a persistent data file in a C++ Google unit test, such that the file is accessible after the test runs?

Code and desired behavior

I'm running the unit test on Ubuntu 14.04 with catkin_make. I would like the code to write a file somewhere that I can find it after the test runs. The following code writes a file, but I don't know where it goes, or if it persists after the unit tests complete.

TEST(GUnitTestFileIo, Test_One)
{
  std::ofstream csvFile;
  csvFile.open("helloWorldTestFile.csv");
  if (csvFile.is_open()) {
    csvFile << "Hello, World, !" << std::endl;
    csvFile.close();
  } else {
    std::cout << "Failed to open the file!" << std::endl;
  }
}

int main(int argc, char **argv){
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}

Answer 1

One solution is to simply write to an absolute file path. The following code writes a file to the user's home directory from inside of a google unit test:

TEST(GUnitTestFileIo, Test_One)
{
  char const* tmp = getenv( "HOME" );
  if ( tmp == NULL ) {
    std::cout << "$(HOME) environment variable is not defined!";
  } else {
    std::string home( tmp );  // string for the home directory
    std::ofstream csvFile;  // write the file
    csvFile.open(home + "/helloWorldTestFile.csv");
    if (csvFile.is_open()) {
      csvFile << "Hello, World, !" << std::endl;
      csvFile.close();
    } else {
      std::cout << "Failed to open the file!" << std::endl;
    }
  }
}

// Run all the tests that were declared with TEST()
int main(int argc, char **argv){
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}