I did a quick google search for 'parse C++ header file with perl' and came up with quite a few good results. My suggestion is that you:

• find a script that already generates a data structure from a header file ( like this one: http://starship.python.net/crew/tbryan/PERCEPS/ ) ( or http://aips2.nrao.edu/RELEASED/cxx2html/ )
• use Data::Dumper to view the data structure that is created.
• use a templating system such as Template toolkit to layout your functions and classes.

This way you will be able to take an iterative approach to the development of your tool and it is a good method to build your perl skills as you go.

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Clayton