Keeping blank lines in C++ preproccessor output

[galexander2@nc.rr.com]

I'm using the C++ preprocessor (g++ -E) to partially preprocess a C++ header file.  The preprocessor output documentation (http://gcc.gnu.org/onlinedocs/gcc-4.5.1/cpp/Preprocessor-Output.html) states:

  Long runs of blank lines are discarded.

Rather than have long runs of blank lines discarded, I would prefer that runs of two or more blank lines be replaced by single blank line or that blank lines be left as is.  Does anyone know of a way to accomplish either of these?

Thanks,
Geoff Alexander