I don't know SWIG at all - perhaps there are others here that can offer advice. But on most of the forums (fora ?) that I peruse there's not much advice forthcoming wrt SWIG - though there are plenty that are willing and able to offer good advice wrt Inline::C and Inline::CPP.

The function prototype would suggest that the task is trivial with Inline::C (or Inline::CPP) - so maybe try that path if you don't get a helpful answer to the question that you actually asked.

My hunch is that something like '$ret = sendMsg("hello", $response, $respsize);' ought to work if $respsize is set to the appropriate value .... but I'm really going out on a limb ... and a very thin one at that ... in fact I can feel it breaking away as I'm typing ...

Cheers,
Rob