Re: [PATCH] md5sum: add an option to change directory

[Bernhard Voelker]

On 2020-05-31 00:31, Assaf Gordon wrote:
> Hello,
> 
> On 2020-05-30 3:59 p.m., Bertrand Jacquin wrote:
> [...]
>> This definitely make sense
>>
>>>>    $ sha256sum -C /etc fstab
>>>>    b5d6c0e5e6bc419b134478ad7b3e7c8cc628049876a7772cea469e81e4b0e0e5
>>>> fstab
>>>
>>> The net effect is that just the output has changed to omit the path
>>> name.
>>>
>>> Maybe this wants to be a --strip or -p option like with diff or patch,
>>> or --basename-only to strip a variable number of components, leaving
>>> only
>>> the last.
>>
>> This seems to be a better approach indeed. I just sent a new patch using
>> base_name from coreutils itself.

@Bertrand: thanks for the report and especially the patch: this is a very
positive example to have something concrete for discussion.

> The GNU Datamash program can do basename and dirname on a column of a 
> text file, producing the wanted results (and more):
> 
>   $ md5sum /etc/fstab world.txt | datamash -W --full basename 2 dirname 2
>   b50f98cdf2d6e26a99040ad5386b0884  /etc/fstab  fstab      /etc
>   b1946ac92492d2347c6235b4d2611184  world.txt   world.txt  .
> 
> And this will work on any input without the need to duplicate
> functionality in multiple programs.

Indeed, this is yet another of the many ways to strip the file name as already
mentioned.  Furthermore, adding such a new option would therefore not only add
code complexity, but also break the usual case where a *sum tool creates a
list of checksums which then can be verified in another run with the -c option.
Thus, I'm not so enthusiastic either to add such an option.

Have a nice day,
Berny