I am not able to get them to work on Mac OS. I tried hdf5plugin-1.10.7-osx1013_64-clang.tar.gz and hdf5plugin-1.10.7-osx1013_64-intel.tar.gz. Both provided “.so” files (e.g., libh5blosc.so) but I believe on Macintosh I need .dylib files. I have not been able to find .dylib files.
I have installed the .so files in the right place ("/usr/local/hdf5/lib/plugin") but they are not found by the HDF5 library.
Even with hdf5plugin-1.10.7-osx1013_64-clang.tar, the README file talks about Linux and Windows but nothing about Mac. So I’m starting to think that dynamically loaded filters are not supported on Mac.
I run on mac too (macOS 10.14) and I would not say that .dylib files are a requirement. That is the macOS native way of doing shared libs but I’ve used .so files for HDF5 plugins fine on macOS.
Have you used the HDF5_PLUGIN_PATH environment variable to inform HDF5 library where to go look for plugins? Also, if you set the HDF5_DEBUG environment variable (https://support.hdfgroup.org/HDF5/doc/H5.user/Debugging.html) to “all”, you might get some hints from the library about why its not finding your plugin shared libs.
My program has a command that dumps collected HDF5 library error messages. Using this I saw:
_While executing HDF5LoadData, H5Dread failed. (HDF5 Library Error -1)
_HDF5 library function H5PL__open(): can’t dlopen:dlopen(/usr/local/hdf5/lib/plugin/libh5blosc.so, 5): Library not loaded: @rpath/libhdf5.103.dylib
_ Referenced from: /usr/local/hdf5/lib/plugin/libh5blosc.so
_ Reason: image not found
From that I can tell that the Mac dynamic loader is trying to load the .so file and that the .so file is looking for a library named libhdf5.103.dylib.
My application ships with a library named libhdf5.dylib in the Frameworks folder of the application bundle. After about two hours of floundering and trial-and-error (with rpath and loader_path), I finally found the magic incantation:
This tells libh5blosc.so to look for hdf5lib.dylib in the Frameworks folder of the bundle of the currently-running application. And it worked!
I did this for all of the .so files in /usr/local/hdf5/lib/plugin using this command:
for file in /usr/local/hdf5/lib/plugin/*.so; do install_name_tool -change “@rpath/libhdf5.103.dylib” “@executable_path/…/Frameworks/libhdf5.dylib” “$file”; done
Loadable modules are called “bundles” in Mach-O speak. They have the file type MH_BUNDLE. They can carry any extension; the extension .bundle is recommended by Apple, but most ported software uses .so for the sake of compatibility.
So a .so file that runs on Macintosh is a Mach-O file despite the fact that .so on Unix is an ELF file.
The command “otool -hv” reports the filetype of HDF5 dynamically loaded filter files (e.g., libh5blosc.so) as BUNDLE. This stands for MH_BUNDLE which is described in the Mach-O loader.h file as “dynamically bound bundle file”.
To make matters more confusing, this type of bundle is not the same as a CFBundle which is “is a file directory with a defined structure and file extension, allowing related files to be grouped together as a conceptually single item”.
