[netCDF #MJR-379092]: more information about segmentation fault in ncdump when dumping HDF5 string
- Subject: [netCDF #MJR-379092]: more information about segmentation fault in ncdump when dumping HDF5 string
- Date: Fri, 23 Mar 2012 11:31:38 -0600
Thanks for all your work on isolating the bug.
I think the problem may be that netCDF-4 has no such type
as a "fixed length string", it only has the "string" type,
which is always variable length, and an "array of char"
type, which was in the netCDF-3 classic model, and for
which a dimension must be defined and named to identify
the langth of the char array.
When Ed added support for reading HDF5 files that were not
netCDF-4 files, he may have not realized fixed-length chars
were a new type that the netCDF-4 data model does not support.
They either have to be converted to variable length strings
(perhaps with a hidden attribute indicating they are fixed
length) or as array of char, with a new dimension defined
that does not correspond to an associated HDF5 dataspace.
Or, we have to add support for a new type, which is a lot of
The netCDF-4 data model supports fixed-size arrays as members
of structs, without having to define associated named dimensions.
But as far as I understand, it does not support fixed-size arrays
that have no associated, named dimensions.
I'll have to look at this a little more carefully to verify that
the problem is in the netCDF-4 library layer rather than ncdump,
but if so, the fix will have to be in the library.
Russ Rew UCAR Unidata Program
Ticket ID: MJR-379092
Department: Support netCDF