git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: Dan Jacques <dnj@google.com>
Cc: git@vger.kernel.org, gitster@pobox.com, Johannes.Schindelin@gmx.de
Subject: Re: [PATCH v6 2/3] Makefile: add Perl runtime prefix support
Date: Mon, 19 Mar 2018 20:21:25 +0100	[thread overview]
Message-ID: <87y3inc1my.fsf@evledraar.gmail.com> (raw)
In-Reply-To: <20180319025046.58052-3-dnj@google.com>


On Mon, Mar 19 2018, Dan Jacques jotted:


> +# BEGIN RUNTIME_PREFIX generated code.
> +#
> +# This finds our Git::* libraries relative to the script's runtime path.
> +sub __git_system_path {
> +	my ($relpath) = @_;
> +	my $gitexecdir_relative = '@@GITEXECDIR_REL@@';
> +
> +	# GIT_EXEC_PATH is supplied by `git` or the test suite.
> +	my $exec_path = $ENV{GIT_EXEC_PATH};
> +	if ($exec_path eq "") {
> +		# This can happen if this script is being directly invoked instead of run
> +		# by "git".
> +		require FindBin;
> +		$exec_path = $FindBin::Bin;
> +	}

I think it would be more idiomatic and more paranoid (we'll catch bugs)
to do:

    my $exec_path;
    if (exists $ENV{GIT_EXEC_PATH}) {
        $exec_path = $ENV{GIT_EXEC_PATH};
    } else {
        [...]
    }

I.e. we're interested if we got passed GIT_EXEC_PATH, so let's see if it
exists in the env hash, and then use it as-is. If we have some bug where
it's an empty string we'd like to know, presumably...

> +
> +	# Trim off the relative gitexecdir path to get the system path.
> +	(my $prefix = $exec_path) =~ s=${gitexecdir_relative}$==;

The path could contain regex metacharacters, so let's quote those via:

    (my $prefix = $exec_path) =~ s/\Q$gitexecdir_relative\E$//;

This also nicely gets us rid of the more verbose ${} form, which makes
esnse when we're doing ${foo}$ instead of the arguably less readbale
$foo$, but when it's \Q$foo\E$ it's clear what's going on.

  parent reply	other threads:[~2018-03-19 19:21 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-19  2:50 [PATCH v6 0/3] RUNTIME_PREFIX relocatable Git Dan Jacques
2018-03-19  2:50 ` [PATCH v6 1/3] Makefile: generate Perl header from template file Dan Jacques
2018-03-19  3:07   ` Eric Sunshine
2018-03-19  2:50 ` [PATCH v6 2/3] Makefile: add Perl runtime prefix support Dan Jacques
2018-03-19 17:14   ` Junio C Hamano
2018-03-19 17:21     ` Daniel Jacques
2018-03-19 19:12   ` Ævar Arnfjörð Bjarmason
2018-03-19 19:14     ` Daniel Jacques
2018-03-19 19:17       ` Daniel Jacques
2018-03-19 20:41         ` Junio C Hamano
2018-03-19 19:21   ` Ævar Arnfjörð Bjarmason [this message]
2018-03-19 19:47     ` Daniel Jacques
2018-03-19 21:32   ` Martin Ågren
2018-03-19 22:07     ` Daniel Jacques
2018-03-19  2:50 ` [PATCH v6 3/3] exec_cmd: RUNTIME_PREFIX on some POSIX systems Dan Jacques
2018-03-19 17:24   ` Junio C Hamano
2018-03-19 17:30     ` Daniel Jacques
2018-03-19 19:27   ` Ævar Arnfjörð Bjarmason
2018-03-19 19:38     ` Daniel Jacques
2018-03-19 17:02 ` [PATCH v6 0/3] RUNTIME_PREFIX relocatable Git Junio C Hamano
2018-03-19 19:30 ` Ævar Arnfjörð Bjarmason

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=87y3inc1my.fsf@evledraar.gmail.com \
    --to=avarab@gmail.com \
    --cc=Johannes.Schindelin@gmx.de \
    --cc=dnj@google.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --subject='Re: [PATCH v6 2/3] Makefile: add Perl runtime prefix support' \
    /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

Code repositories for project(s) associated with this 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).