Re: [PATCH] CodingGuidelines: drop arithmetic expansion advice to use "$x"

From: Junio C Hamano <gitster@pobox.com>
Date: May 5, 2020, 20:40 UTC
Message-ID: <xmqqr1vy9kv0.fsf@gitster.c.googlers.com>
In-Reply-To: <20200504160709.GB12842@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 15 quoted lines

> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> index 390ceece52..a89e8dcfbc 100644
> --- a/Documentation/CodingGuidelines
> +++ b/Documentation/CodingGuidelines
> @@ -95,10 +95,6 @@ For shell scripts specifically (not exhaustive):
>  
>   - We use Arithmetic Expansion $(( ... )).
>  
> - - Inside Arithmetic Expansion, spell shell variables with $ in front
> -   of them, as some shells do not grok $((x)) while accepting $(($x))
> -   just fine (e.g. dash older than 0.5.4).
> -
>   - We do not use Process Substitution <(list) or >(list).
>  
>   - Do not write control structures on a single line with semicolon.

A new entry in the "What's cooking" report has this:

    * jk/arith-expansion-coding-guidelines (2020-05-04) 1 commit
     - CodingGuidelines: drop arithmetic expansion advice to use "$x"

     The coding guideline for shell scripts instructed to refer to a
     variable with dollar-sign inside airthmetic expansion to work
     around a bug in old versions of bash, which is a thing of the past.
     Now we are not forbidden from writing $((var+1)).

Writing the last sentence made me wonder if we should go one step further and actually encourage actively omitting the dollar-sign from variable reference instead.