The sample code https://gist.github.com/872458 tries to declare the OVERLAPPED struct and ReadFile fcn from http://msdn.microsoft.com/en-us/library/ms684342(v=vs.85).aspx http://msdn.microsoft.com/en-us/library/aa365467(v=vs.85).aspx Lines 19-34 of the gist are wrong and give the following error: C:\Users\Jon\Documents\RubyDev\sandbox>ruby dl_readfile.rb C:/ruby192/lib/ruby/1.9.1/dl/cparser.rb:104:in `parse_ctype': unknown type: OL_OFFSET (DL::DLError) from C:/ruby192/lib/ruby/1.9.1/dl/cparser.rb:33:in `block in parse_struct_signature' from C:/ruby192/lib/ruby/1.9.1/dl/cparser.rb:9:in `each' from C:/ruby192/lib/ruby/1.9.1/dl/cparser.rb:9:in `parse_struct_signature' from C:/ruby192/lib/ruby/1.9.1/dl/import.rb:173:in `union' from dl_readfile.rb:27:in `<module:Win32FileAPI>' from dl_readfile.rb:4:in `<main>' I've tried a couple different nested struct styles but haven't got it to work. How should I define OVERLAPPED? Jon --- blog: http://jonforums.github.com/ twitter: @jonforums