netdev - Re: [PATCH iproute2 1/2] configure: avoid un-recommended command substitution form

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Message-ID: <ac91d9f3-0651-4c66-9d38-c40281150ac5@gmail.com>
Date: Wed, 27 Dec 2023 22:57:10 -0500
From: Eli Schwartz <eschwartz93@...il.com>
To: Stephen Hemminger <stephen@...workplumber.org>
Cc: netdev@...r.kernel.org
Subject: Re: [PATCH iproute2 1/2] configure: avoid un-recommended command
 substitution form

On 12/27/23 7:46 PM, Stephen Hemminger wrote:
> On Sun, 17 Dec 2023 22:30:52 -0500
> Eli Schwartz <eschwartz93@...il.com> wrote:
> 
>> The use of backticks to surround commands instead of "$(cmd)" is a
>> legacy of the oldest pre-POSIX shells. It is confusing, unreliable, and
>> hard to read. Its use is not recommended in new programs.
>>
>> See: http://mywiki.wooledge.org/BashFAQ/082
>> ---
> 
> This is needless churn, it works now, and bash is never going
> to drop the syntax.

Per the patch message, the reason to avoid the syntax is because it is
confusing, unreliable, and hard to read.

It was deprecated for good reason, and those reasons are relevant to
people writing shell scripts! Regardless of whether it is removed, it
has several very sharp edges and the modern alternative was designed
specifically because the legacy syntax is bad to use *even in bash*.

(bash has nothing to do with it. But also, again, this is not about bash
because the configure script shebang is *not* /bin/bash.)

-- 
Eli Schwartz