Re: [PATCH v6 00/11] Fix icase grep on non-ascii

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 22, 2016, 18:36 UTC
Message-ID: <CAPc5daWEoK4Gp138VPstqwCAX+2K=_gSW98brHjmJYNWK4dkZw@mail.gmail.com>
In-Reply-To: <CACsJy8BQxAkpoT7GVNgtM-0n1pMZeV5TRCiSn6TsYeATWeU=EA@mail.gmail.com>

On Wed, Jun 22, 2016 at 11:29 AM, Duy Nguyen <pclouds@gmail.com> wrote:

Show 12 quoted lines

>
> Can any shell wizards explain this to me? With this code
>
> BS=\\
> echo ${BS}${BS}
>
> Debian's dash returns a single backslash while bash returns two
> backslashes. Section 2.2.1 [1] does not say anything about one
> backslash (hidden behind a variable!) after escaping the following one
> and still eats the one after that..
>
> [1] http://pubs.opengroup.org/onlinepubs/009604499/utilities/xcu_chap02.html

I am not a wizard, but is the difference between the shell syntax, or just their implementation of builtin-echo? IOW, how do these three compare?

printf "%s\n" "${BS}${BS}" echo "${BS}${BS}" echo ${BS}$BS}