git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: "Johannes Sixt" <j6t@kdbg.org>,
	"Philippe Blain" <levraiphilippeblain@gmail.com>,
	"René Scharfe" <l.s.r@web.de>,
	"Git Mailing List" <git@vger.kernel.org>
Subject: Re: [PATCH] t3920: don't ignore errors of more than one command with `|| true`
Date: Wed, 23 Nov 2022 09:55:07 +0900	[thread overview]
Message-ID: <xmqq1qpupk0k.fsf@gitster.g> (raw)
In-Reply-To: <221123.86ilj6a8ux.gmgdl@evledraar.gmail.com> ("Ævar Arnfjörð Bjarmason"'s message of "Tue, 22 Nov 2022 23:57:20 +0100")

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> We have that "sed -n -e" in somewhat wide use:
>
> 	$ git grep 'sed (-n -e|-ne).*/p.*&&' | wc -l
> 	54
>
> The only existing occurance of this "grep but ignore the exit code" I
> could find was:
>
> 	t/t9001-send-email.sh:  { grep '^X-Mailer:' out || :; } >mailer &&
>
> For which we can also:
>
> 	-       { grep '^X-Mailer:' out || :; } >mailer &&
> 	+       sed -ne '/^X-Mailer:/p' <out >mailer &&
>
> And which I'd think would be great to have in a re-roll, i.e. "here's
> these two cases where a grep-but-dont-care-about-the-exit-code could be
> replaced by sed -ne".
>
> But if re-testing this is tedious etc. I don't mind if it goes in as-is,
> but then I'd think we could safely emulate the t9001-send-email.sh
> pattern of using ":" instead of "true"; we don't need to invoke another
> process just to ignore the exit code.

Let's leave all of the above (mostly good ideas) for "after the dust
settles" clean-up.

If sed is much slower than grep (for such a small string use case,
start-up cost of a process would dwarf everybody else), "grep || :"
might be justifiable, but other than that I do not think of a good
reason why we might favor "grep || :" offhand over "sed -ne //p".




  reply	other threads:[~2022-11-23  0:55 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-21 17:58 [PATCH] t3920: don't ignore errors of more than one command with `|| true` Johannes Sixt
2022-11-21 22:56 ` René Scharfe
2022-11-22  0:53   ` Junio C Hamano
2022-11-22 18:28 ` Philippe Blain
2022-11-22 22:24 ` Ævar Arnfjörð Bjarmason
2022-11-22 22:37   ` Johannes Sixt
2022-11-22 22:57     ` Ævar Arnfjörð Bjarmason
2022-11-23  0:55       ` Junio C Hamano [this message]
2022-12-02 16:51 ` [PATCH 2/1] t3920: support CR-eating grep René Scharfe
2022-12-02 23:14   ` Philippe Blain
2022-12-03  7:09     ` René Scharfe
2022-12-02 23:32   ` Eric Sunshine
2022-12-03  7:12     ` René Scharfe
2022-12-05  1:08   ` Junio C Hamano
2022-12-05  8:28     ` René Scharfe
2022-12-05  9:32       ` Junio C Hamano
2022-12-05 10:43         ` René Scharfe
2022-12-02 16:51 ` [PATCH 3/1] t3920: simplify redirection of loop output René Scharfe
2022-12-02 16:51 ` [PATCH 4/1] t3920: replace two cats with a tee René Scharfe
2022-12-03  5:09   ` Eric Sunshine
2022-12-03  8:43     ` René Scharfe
2022-12-03 12:53       ` Ævar Arnfjörð Bjarmason
2022-12-03 17:22         ` René Scharfe
2022-12-04  9:34           ` Ævar Arnfjörð Bjarmason
2022-12-04 16:39             ` Eric Sunshine

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqq1qpupk0k.fsf@gitster.g \
    --to=gitster@pobox.com \
    --cc=avarab@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=j6t@kdbg.org \
    --cc=l.s.r@web.de \
    --cc=levraiphilippeblain@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).