[Top] [Prev] [Next]

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
 The hdfpack option flags are described in Table 15J.

TABLE 15J
-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.

hdfpack Option Flags

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

[Top] [Prev] [Next]

hdfhelp@ncsa.uiuc.edu
HDF User's Guide - 05/19/99, NCSA HDF Development Group.