Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20181107022156.GA254567@google.com> <alpine.DEB.2.21.999.1811061845161.5308@trent.utfs.org>
 <CA+ASDXPMMXCBN6PU8qzRm579sC9VBdwnxZdZwRdPY1cBUP8oGQ@mail.gmail.com>
 <20181107184435.GA168339@google.com> <20181107.204358.257636196@genki.is>
 <20181107205514.GB12273@roeck-us.net> <20181107.210731.330601031@genki.is>
 <CAD=FV=Wcxf7p1DyJdVEqODbc6TdTtbPiLszWCAS1xC6=4kkLbw@mail.gmail.com>
 <CA+ASDXN40pvbZKvsO3Cb8256AQJ3fyQh5TWdT+GDk_ncq11nMw@mail.gmail.com>
 <CAK7LNAR5etb-oJDaxNZbH9-FmC3+hC3A_cwnbuWPQx0maHaDng@mail.gmail.com>
 <20181109183436.GA45531@google.com> <20181110.085826.230851261@genki.is>
 <m24lcpjjss.fsf@linux-m68k.org> <20181110.201050.925673938@genki.is> <CAJ1xhMXDFAdiWMV6ODcJM8bfjs-ddyv8utf6N+Yh7+-Ne-KaHw@mail.gmail.com>
In-Reply-To: <CAJ1xhMXDFAdiWMV6ODcJM8bfjs-ddyv8utf6N+Yh7+-Ne-KaHw@mail.gmail.com>
From:   Alexander Kapshuk <alexander.kapshuk@gmail.com>
Date:   Sun, 11 Nov 2018 17:03:29 +0200
Message-ID: <CAJ1xhMWh15L62wv+bKMzvEUEvLbj-PTZQ0g=AzY3BzkvfikzBQ@mail.gmail.com>
Subject: Re: [PATCH] scripts/setlocalversion: Improve -dirty check with
 git-status --no-optional-locks
To:     sky@genki.is
Cc:     schwab@linux-m68k.org, briannorris@chromium.org,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        dianders@chromium.org, Guenter Roeck <linux@roeck-us.net>,
        lists@nerdbynature.de, linux-kernel <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sun, Nov 11, 2018 at 4:48 PM Alexander Kapshuk
<alexander.kapshuk@gmail.com> wrote:
>
> On Sat, Nov 10, 2018 at 10:12 PM Genki Sky <sky@genki.is> wrote:
> >
> > Hi Andreas,
> >
> > On Sat, 10 Nov 2018 11:42:11 +0100, Andreas Schwab <schwab@linux-m68k.org> wrote:
> > > On Nov 10 2018, Genki Sky <sky@genki.is> wrote:
> > > > On Fri, 9 Nov 2018 10:34:37 -0800, Brian Norris <briannorris@chromium.org> wrote:
> > > >> +          git_status="$(git --no-optional-locks status -uno --porcelain 2>/dev/null)"
> > > >> +          if [ $? -eq 0 ]; then
> > > >> +                  if echo "$git_status" | grep -qv '^.. scripts/package'; then
> > > >
> > > > Shouldn't this be:
> > > >
> > > >     if printf '%s' "$git_status" | grep -qv '^.. scripts/package'; then
> > > >
> > > > I.e., use printf not echo? Because of echo introducing a newline.
> > >
> > > The input to grep should be a text file, thus should end with a newline.
> >
> > Ah okay, thanks. I guess GNU grep was being lenient. Well then, I
> > think the line at least needs to be changed to:
> >
> >         if [ -n "$git_status" ] && echo "$git_status" | grep -qv '^.. scripts/package'; then
> >
> > I'm just trying to say that in the proposed patch, if git doesn't
> > print anything, the echo adds a newline that wasn't there before. This
> > causes the grep -qv to exit with status 0 (because there's at least
> > one line that doesn't contain '^.. scripts/package'). Meaning it will
> > print dirty.
>
> Piping the output of the git command to grep and using the return status
> of grep as the test condition within the if block, would be sufficient
> to determine whether or not '-dirty' should be printed.
>
> Sample run:
> % if git --no-optional-locks \
>         status -uno --porcelain \
>         2>/dev/null |
>         grep -qv '^.. scripts/package'
> then
>         printf '%s' -dirty
> fi
> %

To improve the readability, the git command may be stored in a variable
and substituted into a command within the if block like so:

% cmd='git
--no-optional-locks
status
-uno
--porcelain'

% if $cmd 2>/dev/null | grep -qv '^.. scripts/package'; then
        printf '%s' -dirty
fi
%