On Feb 6, 2012, at 3:15 AM, Jeffrey Jones wrote:

> Hello all,
> 
> I am in the early stages of investigating ruby FFI for use with a
> particular third party library.
> 
> This library makes use of a few functions with the following
> signature.
> 
> struct * function (unsigned char*, unsigned int)
> 
> These functions are basically used for reading data in from various
> places (fread for example) so it is the data itself and the data size.
> 
> Looking at all the various documentation and examples and code, I
> cannot actually see what I need to do in ruby to match the signature.
> 
> module Foo
>  attach_function :function, [:uchar, :uint], :pointer
> end
> 
> Doesn't work because it isn't expecting a single char but a char*.
> 
> Does anyone know what I need to do? (If it is even possible?)

A "char *" is a pointer. You almost had the answer on your own.

module Foo
  attach_function :function, [:pointer, :uint], :pointer
end

Try that.

cr