GNU bug report logs - #45648
`dd` seek/skip which way is up?

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From: Bernhard Voelker <mail <at> bernhard-voelker.de>
To: Bela Lubkin <bela.lubkin <at> gmail.com>, 45648 <at> debbugs.gnu.org
Subject: bug#45648: `dd` seek/skip which way is up?
Date: Tue, 5 Jan 2021 00:07:39 +0100

On 1/4/21 4:03 AM, Bela Lubkin wrote:
> I constantly confuse 'seek=N' and 'skip=N'.  The two words have no natural
> affinity to one I/O direction or the other.

While the words 'seek' and 'skip' may not be strong enough for everyone
to be clear about whether they apply on input or output - e.g. for non-native
English speaker like myself - they are well documented in usage() and more places:

  $ dd --help | grep -E ' (skip|seek)=N '
    seek=N          skip N obs-sized blocks at start of output
    skip=N          skip N ibs-sized blocks at start of input

FWIW these terms are required by POSIX:

  https://pubs.opengroup.org/onlinepubs/9699919799/utilities/dd.html

> I previously encountered a `dd` implementation which also accepted
> 'oseek=N' and 'iseek=N', which I found far more natural and easy to
> remember.

What 'dd' implementation was this specifically?

> Here is a small patch implementing the same for coreutils `dd`.

In my opinion: if the word chosen for an option is not clear enough
to distinguish from another one, then adding yet another alias would
just increase confusion.

Adding options to coreutils programs has to be carefully chosen.
The only reason I'd see to add such an alias would be existing
behavior in one of the other major implementations.

Have a nice day,
Berny

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