		Building and installation instructions for Alpha Open VMS
                              HDF5 1.8.12 release
                               18 September 2013
   


		CONTENTS
		--------
                
		1. Obtaining HDF5
		2. Building and testing HDF5 C, Fortran and C++ libraries,
                   and utilities
		3. Installing HDF5 libraries
		4. Known problems


	1.Obtaining HDF5

	  Please see INSTALL file in this directory for downloading instructions.

	2. Building and testing HDF5 C, Fortran and C++ libraries and utilities.

           IMPORTANT: This version REQUIRES GNU ZLIB library to be installed
                      on a system. You may download the source code from
                      http://www.zlib.net/

                      The newest ZLIB 1.2.8 doesn't work properly on OpenVMS.
                      But ZLIB 1.2.5 works fine.

	 -  Use tar command to untar HDF5 source ball

		tar -xvf <source>.tar

	 -  Change default directory to [.<source>.vms]
         -  Specify top HDF5 source directory in the build.com file where the 
            "hdf5top" is defined.
         -  Edit make.com:
         	specify path to ZLIB library
        	if necessary, modify compilation flags 
	    Do NOT REMOVE /define=H5_VMS and /standard=strict_ansi qualifiers.
         -  Run build.com command file 
		@build
            We recommend using batch queue to build and test this distribution. 
            The command file runs make.com and builds 
			C library, tests, and utilities	
			Fortran library and tests
			C++ library and tests
            It also runs test scripts to test C, Fortran and C++ libraries, and
	    h5dump, h5diff, h5ls, and h5repack utilities.

	3. Installing HDF5 libraries

	   Modify install.com file to specify installation directory (hdf5top) 
           and run
	       @install
           to install HDF5 C, Fortran, and C++ libraries, and utilities.
           The script will create the directories shown below in the
           installation directory:

           [.HDF5]...
           [.HDF5.INCLUDE]
           [.HDF5.LIB]
           [.HDF5.BIN]
           [.HDF5.EXAMPLES]
           [.HDF5.EXAMPLES.C]
           [.HDF5.EXAMPLES.F90]
           [.HDF5.EXAMPLES.CXX]

           [.HDF5.EXAMPLES.*] directories contain make.com and check.com files 
           to build examples against the installed libraries and to verify 
           the installation.

	4. Known problems

           - There is no support for szip compression filter.
           - Two soft conversion functions (H5T__conv_i_f and H5T__conv_f_i)
             have bugs.  They convert data between floating-point numbers and 
             integers.  But the library's default is hard conversion.  The user 
             should avoid explicitly enabling soft conversion between floating-point 
             numbers and integers. 

	For help contact help@hdfgroup.org
