"This is a strange program of obscure provenance that somehow, still manages to survive in the 21st century."

-> links to wikipedia page with direct discription of lineage back to 5th ed research unix

"That weird bs=4M argument in the dd version isn’t actually doing anything special—all it’s doing is instructing the dd command to use a 4 MB buffer size while copying. But who cares? Why not just let the command figure out the right buffer size automatically?"

Um -

a) it is 'doing the special thing' of changing the block size (not buffer size)

b) Because the command probably doesn't figure out the right size automatically, much like your 'cat' example above which also doesn't

c) And this can mean massive performance differences between invocations

> Another reason to prefer the cat variant is that it lets you actually string together a normal shell pipeline. For instance, if you want progress information with cat you can combine it with the pv command

Umm:

  dd if=file bs=some-optimal-block-size | rest-of-pipeline

that was hard.

>If you want to create a file of a certain size, you can do so using other standard programs like head. For instance, here are two ways to create a 100 MB file containing all zeroes:

  $ uname -sr
  OpenBSD 6.0
  $ head -c 10MB /dev/zero 
  head: unknown option -- c
  usage: head [-count | -n count] [file ...]

well.. guess that wasn't so 'standard' after all.. I must be using some nonstandard version...

  $ man head |sed -ne 47,51p
  HISTORY
     The head utility first appeared in 1BSD.

  AUTHORS
     Bill Joy, August 24, 1977.
  $ sed -ne 4p /usr/src/usr.bin/head/head.c
   * Copyright (c) 1980, 1987 Regents of the University of California.

Hmm..

> So if you find yourself doing that a lot, I won’t blame you for reaching for dd. But otherwise, try to stick to more standard Unix tools.

Like 'pv'?

edit: added formatting, sector size note, head manpage/head.c stuffs.. apologies.