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Date:   Thu, 24 Nov 2022 11:31:54 -0500
From:   Jeff King <peff@peff.net>
To:     Yoichi Nakayama <yoichi.nakayama@gmail.com>
Cc:     Yoichi Nakayama via GitGitGadget <gitgitgadget@gmail.com>,
        git@vger.kernel.org
Subject: Re: [PATCH v4 2/2] git-jump: invoke emacs/emacsclient
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On Thu, Nov 24, 2022 at 09:58:04PM +0900, Yoichi Nakayama wrote:

> > The original vim version used the notation \$1 instead of $1.
> > I'm worried that the emacs version might need the backslash.
> > What does the backslash mean? Is it necessary?
> 
> I found the answer myself. The backslash is to leave the
> evaluation of the argument to the 'eval' execution.
> And another question arose. Why do we use eval?
> What is the difference from running it directly like below?
>     $editor -q $1

The value of $editor is not a single program name, but is itself a shell
command. So you could imagine:

  git config core.editor "some_command --with --args"

or even more complicated shell hackery. From within Git, we'd run it as:

  sh -c "some_command --with --args"

but when you are in a shell already, "eval" is a more efficient way of
doing the same.

-Peff