Re: [PATCH] t/t9902-completion.sh: backslashes in echo

From: Eric Sunshine <sunshine@sunshineco.com>
Date: May 23, 2024, 23:14 UTC
Message-ID: <CAPig+cRme82m-09_yhiMx_O3CgnoAtEZkdFiZTX46yTZ0M0QpQ@mail.gmail.com>
In-Reply-To: <xmqqcypcqgf9.fsf@gitster.g>

On Thu, May 23, 2024 at 7:03 PM Junio C Hamano <gitster@pobox.com> wrote:

Show 14 quoted lines

> Marcel Telka <marcel@telka.sk> writes:
> > There is a problem, but definitely the justification in the commit
> > message is not accurate because we do not care about POSIX here at all.
> > Also maybe it would be better/simpler to use `echo -E` instead of
> > `printf`, but I'm not sure here.
>
> How "portable" is "echo -E"?  It apparently is not listd in [*], but
> it should probably not matter as we are doing this in bash.
>
> printf is a kosher way whose behaviour is pretty well standardized
> especially with respect to "%s".  As I said that I was going to
> merge it down to 'master' already, it is now part of 'master'.
> Use of printf there may hopefully educate folks to think twice
> before using 'echo' on unknown data.

Indeed. Seeing`echo $VAR` used always makes my reading hiccup since it's never immediately clear (without consulting additional context) whether the value of VAR starts with a hyphen or has embedded escapes. On the other hand, `printf "%s" $VAR` doesn't suffer from this problem, so this change is welcome regardless.