write data from a specified device or host memory to a registered file handle.
:param fh: ``CUfileHandle_t`` opaque file handle.
:type fh: intptr_t
:param buf_ptr_base: base address of buffer in device or host memory.
:type buf_ptr_base: intptr_t
:param size: size bytes to write.
:type size: size_t
:param file_offset: file-offset from begining of the file.
:type file_offset: off_t
:param buf_ptr_offset: offset relative to the buf_ptr_base pointer to write from.
:type buf_ptr_offset: off_t
:returns: number of bytes written on success.
:rtype: ssize_t
.. seealso:: `cuFileWrite`
