Tool Name: h5toh4
Syntax:
  `h5toh4 -h`
  `h5toh4` h5file h4file
  `h5toh4` h5file
  `h5toh4 -m` h5file1 h5file2 h5file3 ...
Purpose:
  Converts an HDF5 file into an HDF4 file.
Description:
  `h5toh4` is an HDF5 utility which reads an HDF5 file, h5file, and converts all supported objects and pathways to produce an HDF4 file, h4file. If h4file already exists, it will be replaced.

  If only one file name is given, the name must end in `.h5` and is assumed to represent the HDF5 input file. `h5toh4` replaces the `.h5` suffix with `.hdf` to form the name of the resulting HDF4 file and proceeds as above. If a file with the name of the intended HDF4 file already exists, `h5toh4` exits with an error without changing the contents of any file.

  The `-m` option allows multiple HDF5 file arguments. Each file name is treated the same as the single file name case above.

  The `-h` option causes the following syntax summary to be displayed:

                    h5toh4 file.h5 file.hdf
                    h5toh4 file.h5
                    h5toh4 -m file1.h5 file2.h5 ...

  The following HDF5 objects occurring in an HDF5 file are converted to HDF4 objects in the HDF4 file:

  - HDF5 group objects are converted into HDF4 Vgroup objects. HDF5 hard links and soft links pointing to objects are converted to HDF4 Vgroup references.
  - HDF5 dataset objects of integer datatype are converted into HDF4 SDS objects. These datasets may have up to 32 fixed dimensions. The slowest varying dimension may be extendable. 8-bit, 16-bit, and 32-bit integer datatypes are supported.
  - HDF5 dataset objects of floating point datatype are converted into HDF4 SDS objects. These datasets may have up to 32 fixed dimensions. The slowest varying dimension may be extendable. 32-bit and 64-bit floating point datatypes are supported.
  - HDF5 dataset objects of single dimension and compound datatype are converted into HDF4 Vdata objects. The length of that single dimension may be fixed or extendable. The members of the compound datatype are constrained to be no more than rank 4.
  - HDF5 dataset objects of single dimension and fixed length string datatype are converted into HDF4 Vdata objects. The HDF4 Vdata is a single field whose order is the length of the HDF5 string type. The number of records of the Vdata is the length of the single dimension which may be fixed or extendable.
  Other objects are not converted and are not recorded in the resulting h4file.

  Attributes associated with any of the supported HDF5 objects are carried over to the HDF4 objects. Attributes may be of integer, floating point, or fixed length string datatype and they may have up to 32 fixed dimensions.

  All datatypes are converted to big-endian. Floating point datatypes are converted to IEEE format.

Note:
  The `h5toh4` and `h4toh5` utilities are no longer part of the HDF5 product; they are distributed separately through the page Converting between HDF (4.x) and HDF5.
Options and Parameters:

`-h`
  Displays a syntax summary.
`-m`
  Converts multiple HDF5 files to multiple HDF4 files.
h5file
  The HDF5 file to be converted.
h4file
  The HDF4 file to be created.