> On Dec 11, 2021, at 11:12 AM, u...@mailo.com wrote: > > The article: > https://eklitzke.org/the-cult-of-dd > > The content of the article: > > The Cult of DD > Mar 17, 2017 > You'll often see instructions for creating and using disk images on Unix > systems making use of the dd command. This is a strange program of > [obscure provenance](https://en.wikipedia.org/wiki/Dd_(Unix)) that > somehow, still manages to survive in the 21st century. > > Actually, using dd is almost never necessary, and due to its highly > nonstandard syntax is usually just an easy way to mess things up. For > instance, you'll see instructions like this asking you to run commands > like: > > # Obscure dd version > dd if=image.iso of=/dev/sdb bs=4M > Guess what? This is exactly equivalent to a regular shell pipeline using > cat and shell redirection: > > # Equivalent cat version > cat image.iso >/dev/sdb > 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? > > 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: > > # Cat version with progress meter > cat image.iso | pv >/dev/sdb > There's an obscure option to GNU dd to get it to display a progress > meter as well. But why bother memorizing that? If you learn the pv trick > once, you can use it with any program. > > 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: > > # Obscure dd version > dd if=/dev/zero of=image.iso bs=4MB count=25 > > # Regular head version > head -c 100MB /dev/zero >image.iso > The head command is useful for lots of things, not just creating disk > images. Therefore it's a better investment of your time to learn head > than it is to learn dd. In fact, you probably already know how to use it. > > I will confess: there are some interesting options that dd has, which > aren't easily replicated with cat or head. For instance, you can use dd > to convert a file between ASCII and EBCDIC encodings. 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. > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > End of article and my questions: > > Is the author right in general?
No. > Is the author right for Linux environment? No. > Is the author right for OpenBSD environment? No.
