Re: Shell script cleanups/style changes?

From: David Kastrup <dak@gnu.org>
Date: Aug 3, 2007, 06:13 UTC
Message-ID: <85d4y5w3gm.fsf@lola.goethe.zz>
In-Reply-To: <7vabt9sasl.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano <gitster@pobox.com> writes:

Show 9 quoted lines

>  (1) that shell does not even grok $(cmd) substitution.
>
>      I won't accept a half-baked patch that replaces "$(" with a
>      backtick and matching ")" with another backtick.  You need
>      to at least make sure your interpolated variables within
>      the backtick pair work sensibly, and you haven't broken
>      existing nesting of command interpolations, if any.  I do
>      not even want to inspect, comment on and reject that kind
>      of changes.  Quite frankly, it's not worth my time.

And that's actually not even _half_ of the deal: we are talking about pandering to legacy shells here, and the amount of variance of just what level of quoting/backslashing is needed on the inside of `...` in order to get stuff through with just the right level of quoting is actually stunning.

I've had my fair share of bad surprises with portable scripts. Getting a backquote mechanism running on one shell does not mean it will work on another. Basically, you have to forego nesting stuff and split it out into small units in separate commands.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum