`tar` used to control tape drives too, not news. `dd` has purposes, so the author must not do anything real: 0. Clearing volume tables 1. Creating files of f

`tar` used to control tape drives too, not news. `dd` has purposes, so the author must not do anything real: 0. Clearing volume tables 1. Creating files of fixed sizes 2. Varying block sizes 3. Partial reads 4. Unaligned reads 5. Differing block sizes 6. Character set translation If coreutils' `cp`, `mv`, `dd`, and their friends were modified to support `sendfile(2)` on Linux, these would then use `splice(2)` zero-copy kernel transfers under-the-hood. Already, they're likely hitting caching at some layer but there are advantages when copying between 10+ GbE network devices and/or tmpfs. Furthermore, the major shells `bash`, `zsh`, `fish`, `busybox`, `dash`, and `tcsh` would be advised to use `sendfile(2)` where possible. There's really no need to play bucket-brigade "fire drill" with data when there's a firehose that's free.