H5Fget_filesize() returns the size in bytes of the HDF5 file specified by h5file.
H5Fget_filesize()
h5file
H5Fget_filesize(h5file)
H5IdComponent representing an HDF5 file ID. Typically created via H5Fcreate() or H5Fopen().
H5Fcreate()
H5Fopen()