Newsletter #96

New Features and Changes
Platforms Tested
Known Problems

Release of HDF 4.2r2

We are pleased to announce the release of HDF 4.2r2. It can be downloaded from the following location:

    http://hdfgroup.org/release4/obtain.html

The HDF 4 web page is located at:

    http://hdfgroup.org/products/hdf4/index.html

The documentation for HDF 4.2r2 can be obtained from:

    http://hdfgroup.org/doc.html

The RELEASE.txt file in the source code contains detailed information about this release:

    ftp://ftp.hdfgroup.org/HDF/HDF_Current/src/RELEASE-4.2r2.txt

New Features and Changes

Several new APIs have been added to the SD and GR interfaces:
- - SDreset_maxopenfiles, SDget_maxopenfiles, SDget_numopenfiles:
  For modifying and checking the maximum allowed number of files.
- - SDgetcompinfo, GRgetcompinfo: Gets compression information.
  These functions replaced SDgetcompress and GRgetcompress.
- - SDgetfilename: Retrieves the name of the file, given its ID.
- - SDgetnamelen: Retrieves the length of an object's name, given its ID.
SZIP compression has been added for Fortran, and SZIP compression has also been added to the GR interface.

The problem has been fixed where corruption could occur when a 1-Dimensional SDS had the same name as a dimension. However, be aware that:
- - It is impossible to recover the data that was already corrupted.
- - For existing data that has not been corrupted, the problem was fixed for multi-dimensional SDSs only. If the SDS had only one dimension, the results of subsequent accesses to the dimension would still be unpredictable.

SDS and Vgroup names are no longer limited to 64 characters.

The maximum number of files that can be opened at the same time is no longer limited to 32. In this release, if this limit is reached, the library will increase it to the system limit, minus 3 to account for stdin, stdout, and stderr.

A command-line option (-u) was added to ncdump to enable a user to replace non-alphanumeric characters in SDS names with underscores, if desired. The default behavior is to print what is actually in the file.

New error codes were added to the HDF library. Please refer to the RELEASE.txt file and other HDF4 documentation for more information.

Several new platforms are supported: Mac Intel, FreeBSD 64-bit, Solaris 10 Intel, Linux 2.6 and HP-UX 11.23 (32-bit, 64-bit).

Several changes were made to the HDF configuration, including:
- - The --enable-netcdf flag was introduced.
- - The autotools versions were updated.

Many bugs have been fixed in hrepack and hdiff.

Please refer to the RELEASE.txt file for a comprehensive list of changes in this release.

Platforms Tested

Platforms that were tested with this release are:

   AIX 5.3 (32-bit, 64-bit)
   Free BSD 6.2 (32-bit, 64-bit)
   HP-UX B.11.23 (32-bit, 64-bit)
   IRIX 64 v6.5 (32-bit, 64 bit)
   Linux 2.4, 2.6
   Linux ia64
   Linux x86_64
   Sun OS 5.8, 5.10 (32-bit, 64-bit) 
   Windows XP, Vista
   Mac OS X Intel

For detailed information on platforms and compilers, please refer to the RELEASE.txt file.

Known Problems

hdfcomp fails on HPUX 11.23 for the 64-bit version of the library

This release does not support VMS systems.

N-Bit compression is not supported with Fortran APIs.

Using both fill-value and compression at the same time on an SDS does not work.

When using PGI compilers, make sure that the JPEG library is also compiled with a PGI C compiler; linking with JPEG built with gcc causes JPEG library tests to fail. To bypass the problem:
- - Set LIBS flag to $PGI_JPEG_INSTALL_DIR/lib/libjpeg.a where $PGI_JPEG_INSTALL_DIR points to the installation directory for the PGI-compiled JPEG library:
```
         setenv LIBS $PGI_JPEG_INSTALL_DIR/lib/libjpeg.a
         
```
- - Use the --with-jpeg=$PGI_JPEG_INSTALL_DIR configure flag to configure with the PGI-compiled JPEG library:
```
         ./configure --with-jpeg=$PGI_JPEG_INSTALL_DIR --with-zlib....
         
```

- - Last modified:May 16th 2011