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.