From: Junio C Hamano Date: Wed, 22 Jun 2016 18:36:46 GMT Subject: Re: [PATCH v6 00/11] Fix icase grep on non-ascii Message-ID: In-Reply-To: On Wed, Jun 22, 2016 at 11:29 AM, Duy Nguyen wrote: > > 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}