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15.13 Compressing an HDF File: hdfpack

15.13.1 General Description

The hdfpack utility compresses all of the data in an HDF file and writes the compressed data to a second HDF file.

15.13.2 Command-Line Syntax

hdfpack [-i|-b] [-d number-of-data-descriptors-per-block] [-t number-of-linked-blocks-per-table-entry] input-HDF-filename output-HDF-filename

-b Non-coalesced Blocks

The utility will not coalesce linked-block elements.

-i Interactive Mode

The utility will prompt for each linked-block element.

-d Data descriptors per block

The output file will be created with the specified number of data descriptors per block of data descriptors.

-t Linked-blocks per table entry

The output file will be created with the specified number of linked blocks per table entry.

15.13.3 Examples

To compress the data in the file named "aa.hdf" and store the compressed data in the file named "aa.cmp", use the following hdfpack command:

hdfpack aa.hdf aa.cmp
Suppose a file named "bb.hdf" contains data elements stored as sequences of linked blocks. The following hdfpack command compresses the file while leaving the linked-block elements intact, and writes the compressed data to a file named "bb.blk".

hdfpack -b bb.hdf bb.blk


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hdfhelp@ncsa.uiuc.edu
HDF User's Guide - 07/21/98, NCSA HDF Development Group.