Re: md5sum <FILE produces spurious ` -' in output

[Ian Jackson <ian@davenant.greenend.org.uk>]

Raul Miller writes ("Re: md5sum <FILE produces spurious ` -' in output"):
> It's probably not unreasonable, however, for programs designed to work
> with specifically this md5sum interface to expect the interface to remain
> the same.

When it has already changed more than once (Debian has changed from
old behaviour to new and back and now forward again), and when the
behaviour they'd be insisting on is less convenient for them ?  It
seems unlikely.

> Perhaps there should be a command line argument (of the single hyphen
> single character variety) to output just the md5sum?

Well, one easy anser would be to make
   md5sum - </dev/null
do one thing (new behaviour with spurious `  -') and
   md5sum </dev/null
the other (old bare behaviour).  Indeed, IIRC for a while in some
versions of md5sum they did - I remember removing the `-' argument
from some programs.

>  Perhaps this should
> also work when the file is specified by name?

I think there is no need for this, as if it's only one file you can
nearly always just as easily feed it into stdin.

> This does lose compatability with the historical md5sum, but I'm afraid
> we've already lost that.

Um, we haven't if we just choose to put it back the way it was.  My
point is that the number of programs (Debian and elsewhere) which
still expect and rely on the old better behaviour is significant,
whereas I think the number which _rely_ on the new worse behaviour
(rather than merely coping) will be very small if not zero.

Ian.