Re: [edk2-devel] edksetup.sh: fix for non POSIX whereis(1)

[tlaronde@polynum.com]

Hello Pedro,

Le Mon, Nov 21, 2022 at 10:22:21PM +0000, Pedro Falcato a écrit :
> On Mon, Nov 21, 2022 at 9:21 PM <tlaronde@polynum.com> wrote:
> 
> > diff --git a/edksetup.sh b/edksetup.sh
> > index 06d2f041e6..46b295c430 100755
> > --- a/edksetup.sh
> > +++ b/edksetup.sh
> > @@ -105,6 +105,19 @@ function SetupEnv()
> >    fi
> >  }
> >
> > +# whereis(1) is not a POSIX utility and, for example, its implementation
> > +# in NetBSD is different form the Linux one.
> > +#
> > +function whereis()
> > +{
> > +  (
> > +    IFS=:
> > +    for dir in $PATH; do
> > +      eval ls $dir/${1}* 2>/dev/null || true
> > +    done
> > +  )
> > +}
> >
> Hi Thierry,
> 
> First of all, thanks for the patch! I had noticed this problem when running
> edksetup.sh on a POSIX but not quite Linux system before.
> 
> I kind of dislike your solution. Does NetBSD ship /bin/which by default? I
> think replacing whereis with "which -a" would be a lot better.
> I don't think there's a 100% standard way to do this in POSIX, as which
> isn't POSIX either, and your solution seems... hacky?

The problem is that which -a does not do what is required by the usage
of whereis(1) in the script and what is indeed implemented in Linux whereis(1) (and not in the obsolescent
NetBSD whereis(1)): look for "string*". "which -a python" or "which -a
'python*'" will return nothing.

This is why I ended up with this solution that uses only POSIX sh(1)
features and that is, if I'm not mistaken, an implementation of what is
used.

Best,
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                     http://www.kergis.com/
                    http://kertex.kergis.com/
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