sds_id	IN:	Data set identifier returned by SDcreate or SDselect
	C only:
	cdef	OUT:	Pointer to the chunk definition
	flag	OUT:	Compression flag
	Fortran only:
	dim_length	OUT:	Array of chunk dimensions
	flag	OUT:	Compression flag

	Purpose	Retrieves chunking information for a data set.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	SDgetchunkinfo retrieves chunking information about the data set identified by the parameter sds_id into the parameters cdef and flag in C, and to the parameters dim_length and flag in Fortran.
		Currently, only information about chunk dimensions is retrieved into the corresponding cdef structure element for each type of compression in C, and in the dim_length array in Fortran. No information on compression parameters is available in the comp structure of the HDF_CHUNK_DEF union. Refer to the page on SDsetchunk in this manual for specific information on the HDF_CHUNK_DEF union.
		The value returned in the flag parameter indicates the data set type (i.e., if the data set is not chunked, chunked, and chunked and compressed).
		If the chunk length for each dimension is not needed, NULL can be passed in as the value of the cdef parameter in C.
		The following table shows the type of the data set, possible values of the flag parameter, and the corresponding cdef structure element filled with the chunk's dimensions.

Type of Data Set	Values of flag in C (Fortran)	cdef Structure Element Filled with the Chunk's Dimensions
Not chunked	HDF_NONE (-1)	None
Chunked	HDF_CHUNK (0)	cdef.chunk_lengths[]
Chunked and compressed with either the run-length encoding (RLE), Skipping Huffman or GZIP compression algorithms	HDF_CHUNK | HDF_COMP (1)	cdef.comp.chunk_lengths[]
Chunked and compressed with NBIT compression	HDF_CHUNK | HDF_NBIT (2)	cdef.nbit.chunk_lengths[]

	FORTRAN	integer function sfgichnk(sds_id, dim_length, flag)
		integer sds_id, dim_length(*), flag