Pointer Manipulation

MPI_File_seek
MPI_File_get_position
MPI_File_get_byte_offset

Each process can call the routine MPI_File_seek to update its individual file pointer according to the update mode. The update mode has the following possible values:

• MPI_SEEK_SET - The pointer is set to the offset.

• MPI_SEEK_CUR - The pointer is set to the current pointer position plus the offset.

• MPI_SEEK_END - The pointer is set to the end of the file plus the offset.

The offset can be negative for backwards seeking, but you cannot seek to a negative position in the file. The current position is defined as the elementary data item immediately following the last-accessed data item.

MPI_File_get_position returns the current position of the individual file pointer relative to the current displacement and file type.

MPI_File_get_byte_offset converts the offset specified for the current view to the displacement value, or absolute byte position, for the file.