Re: getopt() argument permuting considered risky

["Michael T Kerrisk" <mtk-lists at gmx dot net>]

> > "Michael T Kerrisk" <mtk-lists@gmx.net> writes:
> >
> >
> > [why argument permutation is bad]
> >
> > > Some suggestions:
> > >
> > > 1. What are the chances of having this feature removed
> > >     from glibc's getopt()?
> > >
> > >    I realise that the argument is probably: "it will
> > >    break existing applications".  Some responses:
> > >
> > >    a) Is that really true: are there really applications
> > >       that depend on this non-standard behaviour?
> >
> > The only difference I see would be that the user would be required to
> > pass option arguments before non-option arguments.
> 
> Yes, but I'm not sure what point you are making?
> 
> > >    b) The existing behaviour is a security risk, as
> > >       described above.
> > >
> > > 2. Perhaps Linux distributors should be setting
> > >    POSIXLY_CORRECT in their default shell start-up
> > >    files?
> >
> > Doing so would also alter lots of useful behavior from various GNU
> > tools.
> 
> This is what I'm not sure of.  Do you know of specific examples?
> 
> (Oops, maybe you're meaning behaviours not related to getopt().
> In that case I see your point, and, yes, it's true.  On first read,
> I thought you were meaning that changing the getopt() behaviour
> would remove the "useful behaviour", but I guess you are
> making the more general point.)

Actually, this makes me think of a third suggestion:

3. Add an environment variable: GETOPT_POSIXLY_CORRECT (or
   somesuch) to specifically affect the behavior of getopt().

Cheers,

Michael

-- 
Michael Kerrisk
mtk-lists@gmx.net

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