dd: copy blocks in reverse order

[Ivan Pozdeev]

Hello Coreutils,

The subj is a requirement if I'm copying between overlapping regions, and the
destination is further in the media than the source.

The specific task I'm having is to move a partition a number of sectors forward.

To be completely clear, the algorithm is: copy a block, then seek to the
previous block (i.e. 2*bs bytes back).

I don't currently see a use case for setting this for input/output 
independently.

An idea for the option name is `d'.

There is a workaround for my particular case - `dd if=<block_device> 
bs=<2*shift_bytes> | dd
of=<block_device> seek=<shift_blocks>' but it requires a few times 
2*shift_bytes of memory.

-- 
Best regards,
 Ivan                          mailto:address@hidden