> -----Original Message----- > From: Eric Blake [mailto:eblake@xxxxxxxxxx] > Sent: Wednesday, November 13, 2013 9:14 PM > To: Chen Hanxiao; libvir-list@xxxxxxxxxx > Subject: Re: [PATCH v2]virsh: track alias option and improve error > message when option duplicates its alias > > In addition to Peter's review, it helps if you make your commit message > smarter by showing before-and-after scenarios, to make it obvious how > the error message improved. My quick testing of the 4 possible 'before' > scenarios: > > $ args="-c test:///default attach-disk test /dev/null vda" > $ tools/virsh $args --shareable --shareable > error: option --mode already seen > $ tools/virsh $args --shareable --mode=shareable > error: option --mode already seen > $ tools/virsh $args --mode=shareable --mode=shareable > error: option --mode already seen > $ tools/virsh $args --mode=shareable --shareable > error: option --mode already seen Thanks for your advice. > > The existing message of "--mode already seen" is absolutely confusing > for scenario 1, correct for scenario 3, and sort of confusing for > scenarios 2 and 4. Your proposed message of "'--shareable' duplicates > its alias '--mode'" would be wrong for scenarios 1 and 3, but works for > scenarios 2 and 4. Are you improving the message for one scenario at > the expense of a regression in quality of other scenarios? I lacked of test cases about two same parameters. > > Furthermore, since aliases are (mostly) undocumented, the ONLY people > that should be using them are historical scripts that already had a > working command line, and not new users trying to experiment with the > various options; and working command lines don't have a problem with > duplicate options. I think you're trying to address a non-issue. Since > neither the '--help' text nor tab completion should be offering an alias > as a preferred spelling in the first place, it's unlikely that a human > user is going to be attempting a collision between its alias and the > canonical spelling. Thanks, I see. If we can get rid of auto completion of alias, I think it will be fine enough. > > I'm inclined to just say leave good enough alone, without trying to make > any further "improvements", as we have reached the point of diminishing > returns. > > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list