Re: [PATCH 15/23] qemu-img: resize: do not always eat last argument

[Michael Tokarev]

20.02.2024 20:57, Daniel P. Berrangé пишет:
> On Sat, Feb 10, 2024 at 12:22:36AM +0300, Michael Tokarev wrote:
> > 'qemu-img resize --help' does not work, since it wants more arguments.
> > Only eat last option at the beginning if it starts like -N.., and allow
> > getopt() to do its work, and eat it up at the end if not already eaten.
> > This will not allow to mix options and size anyway, but it is better
> > than now.
> >
> > Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> > ---
> >   qemu-img.c | 15 +++++++++------
> >   1 file changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/qemu-img.c b/qemu-img.c
> > index 69d41e0a92..929a25a021 100644
> > --- a/qemu-img.c
> > +++ b/qemu-img.c
> > @@ -4271,13 +4271,13 @@ static int img_resize(const img_cmd_t *ccmd, int argc, 
> > char **argv)
> >   
> >       /* Remove size from argv manually so that negative numbers are not treated
> >        * as options by getopt. */
> > -    if (argc < 3) {
> > -        error_exit(ccmd, "Not enough arguments");
> > -        return 1;
> > +    if (argc > 1 && argv[argc - 1][0] == '-'
> > +        && argv[argc-1][1] >= '0' && argv[argc-1][1] <= '9') {
> > +        size = argv[--argc];
> > +    } else {
> > +        size = NULL;
> >       }
>
> We already have a variable 'int relative' that is set to '-1'
> or '+1' depending on whether we have a -ve or +ve size.
>
> I think it is clearer to follow if we just set 'relative' much
> earlier before parsing by moving this chunk of code to before
> the getopt:

Well, we'll also have to repeat the same switch after getopt, since
there, I only test for -[0-9], not +[0-9] or [0-9].   But yes, it
can be done too.

But this is more interesting, - I think we should switch getopt to
use 'return in order' option, and process options together with
getopt, looking at the next option at each iteration, - if it looks
like [+-]size if we already got the filename part.  Lemme try to
do that..

/mjt