How to capture stdout/stderr with googletest?

Question

Is it possible to capture the stdout and stderr when using the googletest framework?

For example, I would like to call a function that writes errors to the console (

Answer 1

Based on the answer of Wgaffa I made this helper class which can be constructed with either std::cout or std::cerr:

class CaptureHelper
{
public:
  CaptureHelper(std::ostream& ioStream)
    : mStream(ioStream),
    mIsCapturing(false)
  { }

  ~CaptureHelper()
  {
    release();
  }

  void capture()
  {
    if (!mIsCapturing)
    {
      mOriginalBuffer = mStream.rdbuf();
      mStream.rdbuf(mRedirectStream.rdbuf());
      mIsCapturing = true;
    }
  }

  std::string release()
  {
    if (mIsCapturing)
    {
      std::string wOutput = mRedirectStream.str();
      mStream.rdbuf(mOriginalBuffer);
      mIsCapturing = false;
      return wOutput;
    }
  }

private:
  std::ostream& mStream;
  bool mIsCapturing;
  std::stringstream mRedirectStream;
  std::streambuf* mOriginalBuffer;

};