Re: [PATCH 1/3] git-bisect: war on "sed"

From: Andreas Ericsson <ae@op5.se>
Date: Nov 15, 2007, 10:06 UTC
Message-ID: <473C1A29.2010703@op5.se>
In-Reply-To: <buotznnesw9.fsf@dhapc248.dev.necel.com>

Miles Bader wrote:

Show 14 quoted lines

> Wincent Colaiuta <win@wincent.com> writes:
>> the shorter form without sed is arguably more readable:
>>
>> -		echo "$head" | sed 's#^refs/heads/##' >"$GIT_DIR/head-name"
>> +		echo "${head#refs/heads/}" >"$GIT_DIR/head-name"
> 
> Er, I suppose -- if you are acquainted with that particular shell
> variable syntax (I suspect knowledge of sed is far more widespread).
> 
> [personally, I know that syntax has something to do with replacing
> something with something else, but really haven't much clue other than
> that, and I always _thought_ it was bash-specific and so avoided using
> any of that stuff.]
>

It says "remove refs/heads/ from the beginning of the string pointed to by $head".

It's not a bashism. Some extensions to that syntax are though (I think). If you want to be sure of portability, use sed instead. git uses this syntax often enough that it's worth using everywhere, but usually only in porcelain commands which one can relatively safely assume are run on at least decently up-to-date developer workstations.

You'll note that stuff that absolutely *has* to reside server-side are entirely in C.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231