From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 17 Sep 2010 18:38:05 GMT
Subject: Re: [PATCH] git-rebase--interactive.sh: LF terminate line sent to cut
Message-ID: <7vsk182p2q.fsf@alter.siamese.dyndns.org>
In-Reply-To: <XhMLJaG8mUbh4rzLnU3IrGDXbMd9-p7UFO6kn9Uke7n_H4NNOG6glg@cipher.nrlssc.navy.mil>

Brandon Casey <brandon.casey.ctr@nrlssc.navy.mil> writes:

> Or we could write it like:
>
>    sha1=${rest%% *}
>
> which I wish I had changed it to in the first place when I made some
> recent modifications.

Agreed; the less use of 'cut' we see, the better ;-)

As to portability guideline in our shell script:

    ${param#word} ${param##word} ${param%word} ${param%%word}

are permissible POSIX constructs (together with more traditional -/=/?/+), and
their use is encouraged over 'cut', 'expr', etc. [*1*]

    ${param:ofs} ${param:ofs:len} ${param/pattern/string}

are bashisms we avoid (unless of course in the bash completion script).

We do not seem to use ${#param}, not because it is forbidden, but I think
because it is not very useful without ${param:ofs:len}.


[Footnote]

*1* In 2005 back when I took over the git maintenance, I used to be a lot
more conservative/traditionalist and as a result, you may see overused
"expr" in contrib/examples/ and "git log -p -- '*.sh'" output.  But we
have been eradicating them a bit by bit for the past few years.