On 10/13/2013 11:31 AM, Hadmut Danisch wrote: > Hi, > > the hashsum check files like sha256sum would be quite usefull (and > improve security), if they could easily be used within shellscripts to > verify downloads. E.g. Ubuntu provides signed hash files like > > http://releases.ubuntu.com/precise/SHA256SUMS > http://releases.ubuntu.com/precise/SHA256SUMS.gpg > > > But one rarely downloads all files, only the needed ones. > > Unfortunately, sha256sum prints warnings and exits with exit status 1 > when files are missing, even when the present files are correct. This > makes checking the files more difficult in shellscripts and might keep > most script authors from checking downloads. > > It would be significantly more usefull and thus more secure if the *sum > commands had an additional option to not report missing files as an > error and to verify just the present files.
This was requested previously: http://lists.gnu.org/archive/html/coreutils/2010-12/msg00032.html The option presented there might work for you? i.e. md5sum -c file.sum 2>/dev/null | grep FAILED$ Another disadvantage to the workaround than stated in the original thread, is that various other md5sum errors might not be diagnosed (like missing file.sum for example). So I'm not against a new option for this, but it warrants discussion. thanks, Pádraig.
