PHYSFS_File man page
PHYSFS_File — A PhysicsFS file handle.
void * opaque
A PhysicsFS file handle.
You get a pointer to one of these when you open a file for reading, writing, or appending via PhysicsFS.
As you can see from the lack of meaningful fields, you should treat this as opaque data. Don't try to manipulate the file handle, just pass the pointer you got, unmolested, to various PhysicsFS APIs.
That's all you get. Don't touch.
Generated automatically by Doxygen for physfs from the source code.
The man page physfs-opaque(3) is an alias of PHYSFS_File(3).