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Hi Charlie, > This is an HDF4 file containing NASA MODIS snow cover data: > http://dust.ess.uci.edu/hdf/MOD10CM.A2007001.005.2007108111758.hdf > > ncdump, compiled with --enable-hdf4, and the netCDF git snapshot from > today, correctly dumps the metadata of the variable > Snow_Cover_Monthly_CMG _unless_ the -s option is given: > > ncdump -s -v Snow_Cover_Monthly_CMG MOD10CM.A2007001.005.2007108111758.hdf > (segfault) > > ncks also dies while trying to dump this metadata. > ncks dies while calling nc_inq_var_chunking(). > I think ncdump dies in that or a similar function, i.e., a function > trying to obtain netCDF4-style information from the variable. > > Is this something that can/should/will be fixed upstream from NCO > such as in the netCDF library or the HDF4 or HDF5 library? Yes, it's a bug in netCDF-4 that we should fix. > Or should NCO develop a workaround, e.g., not attempting "certain > functions" on HDF4 files? If so, which netCDF functions do not > work on HDF4 files? Or, alternatively, which functions does netCDF4 > with --enable-hdf4 support on HDF4 files? And is there any detailed > documentation on what does/doesn't from netCDF on HDF4 files? You shouldn't have to develop a workaround. NetCDF functions that don't work on HDF4 files should return the same way as for netCDF classic format files, either with an error or a sensible value, such as 0 for the number of subgroups or user-defined types. There's not much documentation on how netCDF functions behave with HDF4 files, so we'll have to write some as we fix this problem. I'm opening 2 new issue tickets you can follow if you want to see progress on this or make suggestions on what behaviour you want for specific functions: https://bugtracking.unidata.ucar.edu/browse/NCF-272 https://bugtracking.unidata.ucar.edu/browse/NCF-273 --Russ > Thanks! > c > -- > Charlie Zender, Earth System Sci. & Computer Sci. > University of California, Irvine 949-891-2429 )'( > > Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: HZY-708311 Department: Support netCDF Priority: Normal Status: Closed