git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: ZheNing Hu <adlternative@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: ZheNing Hu via GitGitGadget <gitgitgadget@gmail.com>,
	Git List <git@vger.kernel.org>,
	Christian Couder <christian.couder@gmail.com>
Subject: Re: [PATCH v10 2/2] [GSOC] trailer: add new .cmd config option
Date: Sat, 17 Apr 2021 15:41:17 +0800	[thread overview]
Message-ID: <CAOLTT8S-CLSk6Obu-8L+QKb9YjBufVTMcTnSrfaUOQmyej59TQ@mail.gmail.com> (raw)
In-Reply-To: <xmqqlf9hinuw.fsf@gitster.g>

Junio C Hamano <gitster@pobox.com> 于2021年4月17日周六 上午11:36写道:
>
> Junio C Hamano <gitster@pobox.com> writes:
>
> > And continuing this line of thought, I think it would be a perfectly
> > fine extension to allow the script/program that is launched by the
> > .command or .cmd mechanism to signal interpret-trailers that it does
> > not want it to add a trailer as the result of this invocation by
> > exiting with non-zero.  And that would be a reasonable way forward
> > without having to add yet another ugly workaround .runMode.
> >
> > For example, trailer.signoff.cmd could be this script:
> >
> >       #!/bin/sh
> >       if test $# != 1
> >       then
> >               exit 1
> >       else
> >               git log -1 --author="$1" --format='"%aN" <$aE>'
> >       fi
> >
> > where the "implicit" invocation is signalled by not passing any
> > argument, to which the script reacts by exiting with 1, and the
> > interpret-trailers would discard the result of the unasked-for
> > invocation.
>
> The beauty of this approach, compared to say .runMode, is that the
> program specified by .cmd (and .command, except that it cannot tell
> if the invocation is in response to explicit --trailer=<key>:<value>
> request, or the extra one that is done even without being asked)
> have even better control in squelching the trailer output.  Not just
> to silence the extra unasked-for invocation, it can inspect the
> value given to each of --trailer=<key>:<value> option and decide not
> to add a trailer in response to it.
>

If I understand correctly, Your approach may be like this:

First, Those `<token> <value>` pairs we passed on the command line
will use one positional parameter in the shell-script.

Second, if it is the trailer implicitly added, originally it was
`<token> ""`, now we turn it to `<token> NULL`, This will make
the shell-script not pass positional parameters.

Then our shell script can distinguish them by the value of $#.

If we want shell-script to execute implicitly anyway, We can do nothing.
the shell-script can be like  as Christian mention:

#!/bin/sh
echo "$(git config user.name) <$(git config user.email)>"

But If we want shell-script to reject implicit execution, We can judge the
value of $# : 0 exit , 1 normal as you mention:

#!/bin/sh
if test $# != 1
then
    exit 0
else
    git log -1 --author="$1" --format='%aN <%aE>'
fi

I agree with your approach.
But when I am reproducing your solution, I may be in trouble:
If we let shell-script `exit(1)`, `capture_command()` will output
"running trailer command '%s' failed" which is its origin strategy
in order to catch the user's command error.

But If we use `exit(0)` , The headache is coming again:

Signed-off-by:

the empty value trailer still output. What we want is that those
"<token> NULL" are rejected here, we don’t want any other output,
do we?


Thanks.
--
ZheNing Hu

  reply	other threads:[~2021-04-17  7:41 UTC|newest]

Thread overview: 101+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-23 14:53 [PATCH] [GSOC]trailer: change $ARG to environment variable ZheNing Hu via GitGitGadget
2021-03-24 15:42 ` [PATCH v2] [GSOC]trailer: pass arg as positional parameter ZheNing Hu via GitGitGadget
2021-03-24 20:18   ` Junio C Hamano
2021-03-25  1:43     ` ZheNing Hu
2021-03-25 11:53   ` [PATCH v3] " ZheNing Hu via GitGitGadget
2021-03-25 22:28     ` Junio C Hamano
2021-03-26 13:29       ` ZheNing Hu
2021-03-26 16:13     ` [PATCH v4] " ZheNing Hu via GitGitGadget
2021-03-27 18:04       ` Junio C Hamano
2021-03-27 19:53         ` Christian Couder
2021-03-28 10:46           ` ZheNing Hu
2021-03-29  9:04             ` Christian Couder
2021-03-29 13:43               ` ZheNing Hu
2021-03-30  8:45                 ` Christian Couder
2021-03-30 11:22                   ` ZheNing Hu
2021-03-30 15:07                     ` ZheNing Hu
2021-03-30 17:14                       ` Junio C Hamano
2021-03-31  5:14                         ` ZheNing Hu
2021-03-31 18:19                           ` Junio C Hamano
2021-03-31 18:29                             ` Junio C Hamano
2021-04-01  3:56                               ` ZheNing Hu
2021-04-01 19:49                                 ` Junio C Hamano
2021-04-02  2:08                                   ` ZheNing Hu
2021-04-01  3:39                             ` ZheNing Hu
2021-03-31 10:05       ` [PATCH v5 0/2] " ZheNing Hu via GitGitGadget
2021-03-31 10:05         ` [PATCH v5 1/2] [GSOC] run-command: add shell_no_implicit_args option ZheNing Hu via GitGitGadget
2021-04-01  7:22           ` Christian Couder
2021-04-01  9:58             ` ZheNing Hu
2021-03-31 10:05         ` [PATCH v5 2/2] [GSOC]trailer: pass arg as positional parameter ZheNing Hu via GitGitGadget
2021-04-01  7:28         ` [PATCH v5 0/2] " Christian Couder
2021-04-01 10:02           ` ZheNing Hu
2021-04-02 13:26         ` [PATCH v6] [GSOC] trailer: add new trailer.<token>.cmd config option ZheNing Hu via GitGitGadget
2021-04-02 20:48           ` Junio C Hamano
2021-04-03  5:08             ` ZheNing Hu
2021-04-04  5:34               ` Junio C Hamano
2021-04-03  5:51             ` Christian Couder
2021-04-04 23:26               ` Junio C Hamano
2021-04-06  3:47                 ` Christian Couder
2021-04-06  3:52                   ` Christian Couder
2021-04-06  5:16                     ` ZheNing Hu
2021-04-06  5:34                       ` Junio C Hamano
2021-04-06  5:37                       ` Junio C Hamano
2021-04-04  5:43             ` ZheNing Hu
2021-04-04  8:52               ` Christian Couder
2021-04-04  9:53                 ` ZheNing Hu
2021-04-02 23:44           ` Junio C Hamano
2021-04-03  3:22             ` ZheNing Hu
2021-04-03  4:31               ` Junio C Hamano
2021-04-03  5:15                 ` ZheNing Hu
2021-04-04 13:11           ` [PATCH v7] " ZheNing Hu via GitGitGadget
2021-04-06 16:23             ` Christian Couder
2021-04-07  4:51               ` ZheNing Hu
2021-04-09 13:37             ` [PATCH v8 0/2] [GSOC] trailer: add new .cmd " ZheNing Hu via GitGitGadget
2021-04-09 13:37               ` [PATCH v8 1/2] [GSOC] docs: correct descript of trailer.<token>.command ZheNing Hu via GitGitGadget
2021-04-09 19:02                 ` Christian Couder
2021-04-10 13:40                   ` ZheNing Hu
2021-04-09 13:37               ` [PATCH v8 2/2] [GSOC] trailer: add new .cmd config option ZheNing Hu via GitGitGadget
2021-04-09 20:18                 ` Christian Couder
2021-04-10 14:09                   ` ZheNing Hu
2021-04-09 19:59               ` [PATCH v8 0/2] " Christian Couder
2021-04-12 16:39               ` [PATCH v9 " ZheNing Hu via GitGitGadget
2021-04-12 16:39                 ` [PATCH v9 1/2] [GSOC] docs: correct descript of trailer.<token>.command ZheNing Hu via GitGitGadget
2021-04-12 20:42                   ` Junio C Hamano
2021-04-16 12:03                     ` Christian Couder
2021-04-17  1:54                       ` Junio C Hamano
2021-04-12 16:39                 ` [PATCH v9 2/2] [GSOC] trailer: add new .cmd config option ZheNing Hu via GitGitGadget
2021-04-12 20:51                   ` Junio C Hamano
2021-04-13  7:33                     ` Christian Couder
2021-04-13 12:02                       ` ZheNing Hu
2021-04-13 19:18                         ` Junio C Hamano
2021-04-14 13:27                           ` ZheNing Hu
2021-04-14 20:33                             ` Junio C Hamano
2021-04-15 15:32                               ` ZheNing Hu
2021-04-15 17:41                                 ` Junio C Hamano
2021-04-16 12:54                               ` Christian Couder
2021-04-13 18:14                       ` Junio C Hamano
2021-04-16  8:47                 ` [PATCH v10 0/2] " ZheNing Hu via GitGitGadget
2021-04-16  8:47                   ` [PATCH v10 1/2] [GSOC] docs: correct descript of trailer.<token>.command ZheNing Hu via GitGitGadget
2021-04-16 19:11                     ` Junio C Hamano
2021-04-16  8:47                   ` [PATCH v10 2/2] [GSOC] trailer: add new .cmd config option ZheNing Hu via GitGitGadget
2021-04-16 19:13                     ` Junio C Hamano
2021-04-16 19:21                     ` Junio C Hamano
2021-04-16 19:25                       ` Junio C Hamano
2021-04-17  2:58                         ` Junio C Hamano
2021-04-17  3:36                           ` Junio C Hamano
2021-04-17  7:41                             ` ZheNing Hu [this message]
2021-04-17  8:11                               ` Junio C Hamano
2021-04-17 15:13                   ` [PATCH v11 0/2] " ZheNing Hu via GitGitGadget
2021-04-17 15:13                     ` [PATCH v11 1/2] [GSOC] docs: correct description of .command ZheNing Hu via GitGitGadget
2021-04-17 15:13                     ` [PATCH v11 2/2] [GSOC] trailer: add new .cmd config option ZheNing Hu via GitGitGadget
2021-04-17 22:26                     ` [PATCH v11 0/2] " Junio C Hamano
2021-04-18  7:47                       ` ZheNing Hu
2021-04-21  0:09                         ` Junio C Hamano
2021-04-21  5:47                           ` ZheNing Hu
2021-04-21 23:40                             ` Junio C Hamano
2021-04-22  9:20                               ` ZheNing Hu
2021-04-27  6:49                                 ` Junio C Hamano
2021-04-27 12:24                                   ` ZheNing Hu
2021-05-03 15:41                     ` [PATCH v12 " ZheNing Hu via GitGitGadget
2021-05-03 15:41                       ` [PATCH v12 1/2] [GSOC] docs: correct descript of trailer.<token>.command ZheNing Hu via GitGitGadget
2021-05-03 15:41                       ` [PATCH v12 2/2] [GSOC] trailer: add new .cmd config option ZheNing Hu via GitGitGadget

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=CAOLTT8S-CLSk6Obu-8L+QKb9YjBufVTMcTnSrfaUOQmyej59TQ@mail.gmail.com \
    --to=adlternative@gmail.com \
    --cc=christian.couder@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitgitgadget@gmail.com \
    --cc=gitster@pobox.com \
    --subject='Re: [PATCH v10 2/2] [GSOC] trailer: add new .cmd config option' \
    /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

git@vger.kernel.org list mirror (unofficial, one of many)

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V1 git git/ https://public-inbox.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors.
Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://7fh6tueqddpjyxjmgtdiueylzoqt6pt7hec3pukyptlmohoowvhde4yd.onion/inbox.comp.version-control.git
	nntp://ie5yzdi7fg72h7s4sdcztq5evakq23rdt33mfyfcddc5u3ndnw24ogqd.onion/inbox.comp.version-control.git
	nntp://4uok3hntl7oi7b4uf4rtfwefqeexfzil2w6kgk2jn5z2f764irre7byd.onion/inbox.comp.version-control.git
	nntp://news.gmane.io/gmane.comp.version-control.git
 note: .onion URLs require Tor: https://www.torproject.org/

code repositories for project(s) associated with this inbox:

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

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git