Special attributes for netCDF-4 data

5.11 Special attributes for netCDF-4 data

To display new characterisitics of netCDF-4 data, such as compression and chunking:

the ncdump "-s" option outputs special attributes
special attributes are a CDL syntax to view file characteristics, the special attributes don't really exist
ncgen interprets special attributes in CDL input to set or manipulate the associated file characteristics

The special attributes include:

_ChunkSizes	a list of chunk sizes for each dimension of the variable
_DeflateLevel	an integer between 0 and 9 inclusive if compression was specified for the variable
_Endianness	either `little' or `big', depending on how the variable was stored when first written
_Fletcher32	`true' if the checksum property was set for the variable
_Format	a global attribute specifying the netCDF format variant, one of `classic', `64-bit offset', `netCDF-4', or `netCDF-4 classic model'
_NoFill	`true' if the persistent NoFill property was set for the variable when it was defined
_Shuffle	`true' if use of the shuffle filter was specified for the variable
_Storage	`contiguous' or `chunked', depending on how the variable's data is stored

 $ ncdump -s -h tstd1s.nc