Re: [PATCH] Supplant the "while case ... break ;; esac" idiom

From: Pierre Habouzit <madcoder@debian.org>
Date: Sep 24, 2007, 08:01 UTC
Message-ID: <20070924080134.GA9112@artemis.corp>
In-Reply-To: <86ejgowl5g.fsf@lola.quinscape.zz>

On Mon, Sep 24, 2007 at 07:57:31AM +0000, David Kastrup wrote:

Show 19 quoted lines

> "David Symonds" <dsymonds@gmail.com> writes:
> 
> > On 24/09/2007, David Kastrup <dak@gnu.org> wrote:
> >> Mike Hommey <mh@glandium.org> writes:
> >>
> >> > On Sun, Sep 23, 2007 at 10:42:08PM +0200, David Kastrup wrote:
> >> >> -while case $# in 0) break ;; esac
> >> >> +while test $# != 0
> >> >
> >> > Wouldn't -ne be better ?
> >>
> >> Why?
> >
> > Because -ne does a numeric comparison, != does a string comparison,
> > and it's a numeric comparison happening, semantically speaking.
> 
> I don't see the point in converting $# and 0 into numbers before
> comparing them.  "!=" is quite more readable, and the old code also
> compared the strings.

  Fwiw $# already is a number. Hence test $# -ne 0 is definitely a
better test.

  $# != 0 would yield sth like (strcmp(sprintf("%d", argc), "0"))
  $# -ne 0 would yield sth like (argc != atoi("0")).

  Not that it matters much, but the latter looks better to me.

-- 
·O·  Pierre Habouzit
··O                                                madcoder@debian.org
OOO                                                http://www.madism.org