That’s only true for some environments.

E: this is the first time I’ve read that blog post since it was published (or at least a long time ago) and there’s now a comment specifically referencing the actual behavior I observed in the wild when I tried to sub other things in for “normal” uses of dd:

Nobody says: 2016-12-30 at 15:17

cat /dev/cdrom > myfile.iso

Works

cat myfile.iso > /dev/cdrom

Won’t – dd allows you do handle writes in various block sizes, so if a device can’t handle a one-byte write, cat could well end up writing your byte followed by zeros (and because of where the pointer now is, do it again for the next byte).

Still, all your other points stand – nice piece.

While that comment was written seventy years ago, in this age of people with questionable intent, capability and integrity rewriting system tools in rust there’s no better time to linger thoughtfully over cp or cat or any number of other commands that begin with the letter “c” before grabbing the ol’ reliable footgun whose fifty years of script backwards compatibility ensure that no one can get their dd replacement accepted in normal use until it behaves as expected.