On Tue, Nov 22, 2022 at 4:26 PM <tlaronde@polynum.com> wrote:

> Le Tue, Nov 22, 2022 at 08:40:30AM -0700, Rebecca Cran a écrit :
> > On 11/21/22 15:22, Pedro Falcato wrote:
> >
> > > 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?
> >
> >
> > "command" seems to be the POSIX way to do this?
> > https://pubs.opengroup.org/onlinepubs/9699919799/
> >
> > Though "whereis python3" shows the following on my system:
> >
> > python3: /usr/bin/python3.9-config /usr/bin/python3.9 /usr/bin/python3
> > /usr/lib/python3.9 /usr/lib/python3 /etc/python3.9 /etc/python3
> > /usr/local/lib/python3.9 /usr/include/python3.9 /usr/share/python3
> > /usr/share/man/man1/python3.1.gz
> >
> > "which -a python3" returns:
> >
> > /usr/bin/python3
> > /bin/python3
> >
> > And "command -p -v" returns:
> >
> > /bin/python3
> >
> > I don't know if we need all the results from "whereis"?
>
> The problem is when one does not know which exact version of python
> is here and how, exactly, the command is named.
>
> whereis(1) returns whatever command with python3 as prefix, while
> command or "which -a" will return only exactly python3. If, on the
> system, python is fully version qualified (as is the case with
> pkgsrc, the opt packages framework, used on NetBSD):
>
> which -a python3
>
> will return nothing, since, it is python3.9 for example on the OS.
>

Sorry, what? This sounds so broken. How can a script shebang ever work?

For Sane(tm) systems, I propose command -v python3 + $(command -v python3)
-c 'import sys; print(sys.version.split(" ")[0])',
which gives us the path to the Python 3 interpreter + the path in a
relatively easy, simple way.
I think this could work mostly everywhere but apparently NetBSD since you
don't provide python3? Which makes little sense in my head.

Pedro