From: Chris Torek <chris.torek@gmail.com>
Date: Sat, 04 May 2024 06:51:35 GMT
Subject: Re: [PATCH v2 3/5] ci: separate whitespace check script
Message-ID: <CAPx1GveuQMeKt0_ZuY4DN0_tKrLBjXpWLngxYTtbzV=iHYT-QQ@mail.gmail.com>
In-Reply-To: <ZjUmEuKZB1xwAPo7@ncase>

On Fri, May 3, 2024 at 11:27 PM Patrick Steinhardt <ps@pks.im> wrote:
>
> On Fri, May 03, 2024 at 09:49:13AM -0700, Junio C Hamano wrote:
> > This is a question to Patrick, but what makes it bad to assume
> > "bash" is in "/bin" when it is OK to assume that "env" is always in
> > "/usr/bin"?
>
> My own bias. I know of systems without "/bin/bash" (NixOS), but I don't
> know of any without "/usr/bin/env". But you're right, "/usr/bin/env" is
> not part of POSIX and thus not really portable, either.
>
> Ultimately I don't think there is any way to write the shebang so that
> it is fully POSIX compliant. So I'd rather go with the option which is
> supported on more systems, which is to the best of my knowlede env(1).

The various BSDs mostly stick bash in /usr/local/bin; some versions
of macOS did not have a /bin/bash either, as I recall, though my current
mac-laptop does.

In any case, #! /usr/bin/env <program> is pretty darn common; it's found
in a lot of Python scripts, for instance. It works well on old SunOS, on
the various BSDs, on macOS, and on Linux, provided of course that
the given <program> is installed at all.

The *most* portable method is generally to use only POSIX /bin/sh
constructs, of course. :-)

Chris