Re: [PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

From: Martin Langhoff <martin.langhoff@gmail.com>
Date: Jun 6, 2007, 03:58 UTC
Message-ID: <46a038f90706052058h1c823278o78ce0d8edce3caab@mail.gmail.com>
In-Reply-To: <87sl957naf.fsf@graviton.dyn.troilus.org>

On 6/6/07, Michael Poole <mdpoole@troilus.org> wrote:

Show 14 quoted lines

> Stephen Rothwell writes:
>
> > On Tue, 05 Jun 2007 18:34:59 -0700 Josh Triplett <josh@freedesktop.org> wrote:
> >>
> >> -commits=$(cat ../revs | wc -l | tr -d " ")
> >> +commits=$(wc -l ../revs | tr -d " ")
> >
> > This is not equivalent, you probably wanted:
> >
> > commits=$(wc -l <../revs | tr -d " ")
>
> Which relevant version(s) of wc do not accept filename arguments?
> POSIX[1] seems to specify it.  Or do you mean that there is some
> subtle difference in its processing of stdin vs specified files?

Josh is right. The output *is* different because it contains the filename as well. See

  $ wc < .gitk | tr -d " "
  2177551
  $ wc .gitk | tr -d " "
  2177551.gitk

cheers