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References: <febcfb0a-c410-fb71-cff9-92acfcb269e2@kdbg.org> <203cb627-2423-8a35-d280-9f9ffc66e072@web.de>
In-Reply-To: <203cb627-2423-8a35-d280-9f9ffc66e072@web.de>
From:   Eric Sunshine <sunshine@sunshineco.com>
Date:   Sat, 3 Dec 2022 00:09:25 -0500
Message-ID: <CAPig+cQack=pJ04fwEiq81x6+2AAG4ni0Gd4GQgr4FS=PERb_Q@mail.gmail.com>
Subject: Re: [PATCH 4/1] t3920: replace two cats with a tee
To:     =?UTF-8?Q?Ren=C3=A9_Scharfe?= <l.s.r@web.de>
Cc:     Johannes Sixt <j6t@kdbg.org>,
        Philippe Blain <levraiphilippeblain@gmail.com>,
        Git Mailing List <git@vger.kernel.org>,
        junio C Hamano <gitster@pobox.com>
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On Fri, Dec 2, 2022 at 11:51 AM René Scharfe <l.s.r@web.de> wrote:
> Use tee(1) to replace two calls of cat(1) for writing files with
> different line endings.  That's shorter and spawns less processes.
> [...]
> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
> diff --git a/t/t3920-crlf-messages.sh b/t/t3920-crlf-messages.sh
> @@ -9,8 +9,7 @@ LIB_CRLF_BRANCHES=""
>  create_crlf_ref () {
> -       cat >.crlf-orig-$branch.txt &&
> -       cat .crlf-orig-$branch.txt | append_cr >.crlf-message-$branch.txt &&
> +       tee .crlf-orig-$branch.txt | append_cr >.crlf-message-$branch.txt &&

This feels slightly magical and more difficult to reason about than
using simple redirection to eliminate the second `cat`. Wouldn't this
work just as well?

    cat >.crlf-orig-$branch.txt &&
    append_cr <.crlf-orig-$branch.txt >.crlf-message-$branch.txt &&

(Plus, this avoids introducing `tee` into the test suite, more or
less. The few existing instances are all from the same test author and
don't seem particularly legitimate -- they appear to be aids the
author used while developing the test to be able to watch its output
as it ran.)