Re: [PATCH v2] rebase -i: respect core.commentchar

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 12, 2013, 18:21 UTC
Message-ID: <7vip5xgzp6.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130212175322.GC13501@farnsworth.metanate.com>

John Keeping <john@keeping.me.uk> writes:

Show 14 quoted lines

>> I am not sure if I understand what you meant by "literal backslash
>> blah blah", though.
>
> It turns out that having this in the script works (in bash and dash
> although I haven't checked what Posix has to say about it):
>
>     sed -e "2,$ s/^/\\\/"
>
> and is equivalent to:
>
>     sed -e '2,$ s/^/\\/'
>
> because backslashes that aren't recognised as part of an escape sequence
> are not treated specially.

That's POSIX.  Inside a dq pair:

        \
        The <backslash> shall retain its special meaning as an escape
        character (see Escape Character (Backslash)) only when followed by
        one of the following characters when considered special:
        $   `   "   \   <newline>

So in your example "\\\/", the first backslash escapes the second backslash and together they produce a single backslash, the third backslash is followed by a slash that is not special at all, so it produces a second backslash, and the slash stands for itself, resulting in "\\/".