Re: Enhancement Request for sha256sum - output only the SHA-256 hash alone

[Pádraig Brady]

On 17/07/2020 15:21, jens.archlinux jens wrote:
> Hello,
>
> propose to add a new option for sha256sum to output only the SHA-256 hash
> alone, without a trailing file name and without a trailing newline.
>
> (This would make sense for one input file only).
>
> It would make shell scripts that use sha256sum much simpler. Currently it
> is necessary to split the output of sha256sum to obtain the hash, which
> usually requires an additional command / Unix process.

This is one of those trade-offs.
I'd be 60:40 against adding such an option,
because it's so easy to implement with cut(1):

  sum=$(sha256sum file | cut -d ' ' -f 1)

Yes that's an extra process, but you can easily
enough avoid that on any POSIX shell using:

  sum=$(sha256sum file) && sum=${sum%% *}

cheers,
Pádraig