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meaning of --8<--

Subject: meaning of --8<--

## tl;dr

5 messages between Jan 18, 2009 and Jan 19, 2009.

replies: 4people: 5as markdown or json

Markus Heidelberg· Jan 18, 2009, 15:56 UTC · lore
Hi,

I've seen lines like "--8<--" several times on this list, but have no clue what it is about. OK, seems like it's used to insert diffs in the middle of a mail message. But is this a common convention or git specific and handled by git-am? Is it documented anywhere?

Markus
Peter Harris· Jan 18, 2009, 16:04 UTC · re: Markus Heidelberg · lore

Re: meaning of --8<--

On Sun, Jan 18, 2009 at 10:56 AM, Markus Heidelberg wrote:
Show 5 quoted lines
> I've seen lines like "--8<--" several times on this list, but have no
> clue what it is about. OK, seems like it's used to insert diffs in the
> middle of a mail message.
> But is this a common convention or git specific and handled by git-am?
> Is it documented anywhere?
Common convention, meaning 'cut here'.

Perforated line ------ Scissors 8<

Also used in print (although usually with picture of scissors instead of the ASCII-art).

Peter Harris
Samuel Tardieu· Jan 19, 2009, 11:36 UTC · re: Peter Harris · lore

Re: meaning of --8<--

>>>>> "Peter" == Peter Harris <git@peter.is-a-geek.org> writes:
Peter>  Scissors 8<
One can also use the Unicode character 0x2702: ✂ 
  Sam
-- 
Samuel Tardieu -- sam@rfc1149.net -- http://www.rfc1149.net/
Jay Soffian· Jan 18, 2009, 16:13 UTC · re: Markus Heidelberg · lore

Re: meaning of --8<--

On Sun, Jan 18, 2009 at 10:56 AM, Markus Heidelberg <markus.heidelberg@web.de> wrote:

> Hi,
>
> I've seen lines like "--8<--" several times on this list, but have no
> clue what it is about.

It is supposed to represent a pair of scissors. Sometimes it is the other direction: >8. And I've seen folks botch it as: <8 or 8>. This list is the first (and maybe only?) place I've seen it. Typically you might see:

--snip--
or
--cut--
> But is this a common convention or git specific and handled by git-am?
Seems to be a convention of this list, and git-am does nothing with it afaik.
j.
Jeff King· Jan 18, 2009, 17:44 UTC · re: Markus Heidelberg · lore

Re: meaning of --8<--

On Sun, Jan 18, 2009 at 04:56:37PM +0100, Markus Heidelberg wrote:
Show 5 quoted lines
> I've seen lines like "--8<--" several times on this list, but have no
> clue what it is about. OK, seems like it's used to insert diffs in the
> middle of a mail message.
> But is this a common convention or git specific and handled by git-am?
> Is it documented anywhere?

As others have explained, it is supposed to be scissors, and it is not handled by git-am. But the real point of it is to help the person applying (e.g., Junio) manually separate cover letter from the commit message. So one way of sending cover material is putting it after the "---" and before the diff:

  Subject: [PATCH] first line of commit message
  more commit message
  ---
  Here is cover letter material that doesn't go in the commit message.
  It is stripped automatically by git-am.
  diff --git ...

but that is often unnatural to read, because the cover letter material often introduces the commit, especially when you are replying in the middle of a thread. So then you end up with:

  Subject: Re: whatever thread you're in
  Somebody else said:
  > blah blah blah
  I disagree. You should do it like this instead:
  -- >8 --
  first line of commit message
  more commit message
  ---
  diff --git ...

git-am will put everything down to the "---" into the commit message, but it is simple enough to amend away everything else.

So in that sense, it doesn't really matter _what_ the separator is, but it should be visibly obvious to a human so that they can fix up the commit message. The only exception is that it should _not_ be "---", because that is treated specially by git-am.

-Peff

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