Re: [PATCH 4/1] t3920: replace two cats with a tee

[Eric Sunshine <sunshine@sunshineco.com>]

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.)