HDF_ISHDF function returns
true (1) if the file is a Hierarchical Data Format file and false (0) if the file either is
a Hierarchical Data Format file or does not exist.
This routine bases its judgement as to whether or not a file is an HDF file on the first few bytes of the file. Therefore, it is possible that HDF_ISHDF will identify the file as an HDF file, but HDF_OPEN will not be able to open the file (because it is corrupted).
Result = HDF_ISHDF(
A scalar string containing the name of the file to be tested.