Hi,

this is a bit of a RFC (anlong with a patch). I would like to have an
option in md5sum (and friends) that displays only the digest without
the filename. The use-case is mostly package maintainer scripts. They
often need the md5sum to e.g. check if a conffile has changed and use
patterns like:

  `md5sum /etc/papersize 2> /dev/null | awk '{print $1}'`
  `md5sum /etc/lsb-release | cut -d" " -f1`
  $(md5sum /etc/networks | sed -e 's/ .*//')

Having a --digest-only option in md5sum would make this a bit more
uniform.

Attached is a small patch, if the suggestion gets accepted I'm happy
to flesh it out more and write the man-page entry and tests.

Cheers,
 Michael