dd is a Unix command line utility for copying data. ddpt adds features for
efficiently copying large amounts of data to and from disks. Apart from
accessing disks using traditional Unix read() and write() calls, ddpt can
optionally use SCSI pass-through interfaces to send SCSI commands to perform a
copy. In Linux, the pass-through can be used to send TRIM commands to SSDs. It
is written for Linux with ports to FreeBSD, Solaris, and Windows.

Some features found in ddpt which are not present in the (GNU) dd
implementation:
* sparse writing (i.e. don't write buffer if all zeros)
* write sparing (i.e. don't write buffer if already same as destination)
* resume (after the copy has been interrupted)
* trim on output of copy, self trim (pt interface only)
* send output to a second file (see 'of2=' option)
* access devices directly via pass-through interface, bypassing file system
* accept numeric command line arguments in hexadecimal
* explicit controls over how much data is read into the copy buffer and then
written to output (separate from the logical block sizes of any device
involved)