How can I make Swig correctly wrap a char* buffer that is modified in C as a Java Something-or-other?

Question

I am trying to wrap some legacy code for use in Java and I was quite happy to see that Swig was able to handle the header file and it generate a great wrapper that almost wo

Answer 1

Perhaps this part of the SWIG documentation is helpful:

A common problem in some C programs is handling parameters passed as simple pointers or references. For example:

void add(int x, int y, int *result) {
    *result = x + y;
}

[...]

The typemaps.i library file will help in these situations. For example:

%module example
%include "typemaps.i"

void add(int, int, int *OUTPUT);

There's also a section on wrapping arrays.

I'm sorry this isn't a ready-made, complete answer. SWIG is mind-bending at times.