shred: Option to use random but entire files as source

[Nikita Zlobin]

I know, shred allowes to choose any file to take random bytes from it.
However, there is still one issue, which I found both in articles and
rumors about secure erasing: the fact itself of using such data removal
could be sensitive, and with current approaches (using any of random,
patterns or zero data) it is non-trivial to hide.

Thus, another approach came to my mind - use entire files or their
relatively chunks to overwrite. Following options could present:
- path/file set, allowed as source - siilar to most file search
  indexers like locate, baloo or tracker;
- chunk size range, min and max. If max is unset (e.g. =-1), it would
  mean unlimited maximum size;
- In addition to first - may be have some "weight" kind for different
  paths (even inside anothers), affecting their final priority.

Sure it looks pretty complex, but imho - what yet ever could least
suspicious, than it unwanted area are "uncarefully" get overwritten
during usual file copy/backup ops, due to some fs "bug" :).