[PATCH]: wc: add --total={auto,never,always,only} option

[Pádraig Brady]

On 12/09/2022 17:33, Pádraig Brady wrote:
> On 12/09/2022 16:28, Mike Jonkmans wrote:
> > On Mon, Sep 12, 2022 at 03:45:53PM +0200, Jim Meyering wrote:
> > > On Mon, Sep 12, 2022, 14:53 Pádraig Brady <P@draigbrady.com> wrote:
> > >
> > > > On 12/09/2022 10:20, David Pinto wrote:
> > > > > On Sun, 26 Jun 2022 at 00:49, David Pinto <carandraug+dev@gmail.com>
> > > > wrote:
> > > > > > Hi
> > > > > >
> > > > > > A couple of years ago [1] someone made a feature request for a wc
> > > > > > option that would skip the total line when processing multiple files.
> > > > > > I didn't see anyone commenting against it and it is something that I'm
> > > > > > constantly hacking with `head -n-1`.
> > > > > >
> > > > > > I've attached a patch that implements a new `--no-total` option to wc.
> > > > > > I believe this patch to be trivial enough that I can't claim copyright
> > > > > > for anything.
> > > > > >
> > > > > > Best regards
> > > > > > David
> > > > > >
> > > > > > [1] https://lists.gnu.org/archive/html/coreutils/2015-11/msg00064.html
> > > > >
> > > > > Hi
> > > > >
> > > > > It's been almost 3 months without any reply.  I hope it's OK to bump
> > > > > it again.  I've just changed the subject line to make it clear there
> > > > > is a patch attached.
> > > >
> > > > Thanks for the bump.
> > > >
> > > > This is one of those marginal ones since
> > > > there is no extra functionality provided
> > > > by bringing the logic within the utility.
> > > >
> > > > The following function would achieve the desired functionality:
> > > >
> > > >      wc-no-total() { wc "$@" /dev/null | head -n-2; }
> > > >
> > > > Since it's easy enough to achieve with a single extra processing step,
> > > > Given the above, I'd be 60:40 against adding a --no-total option.
> > > > But thinking more, the above is awkward to combine with the --files0-from
> > > > option.
> > > > So you'd need a separate invocation in that case like:
> > > >
> > > >      { find files -print0; printf '%s\0' /dev/null; } |
> > > >      wc --files0-from=- |
> > > >      head -n2
> > > >
> > > > Even though there is still no extra functionality,
> > > > the above is starting to get a bit obtuse.
> > > >
> > > > If we lifted the restriction with --files0-from
> > > > to also allow file names to be specified on the command line
> > > > (and for those to be processed after stdin),
> > > > it would mean the wc-no-total() function above would be general,
> > > > and would work for all wc invocations.
> > > >
> > > > Though a --no-total option is looking more appealing
> > > > given the above considerations. I.e. that the
> > > > wc-no-total() implementation isn't obvious,
> > > > and we'd have to change wc anyway to make it general.
> > > >
> > > > So I'd be 55:45 for adding this option.
> > >
> > > Good arguments. +1
> >
> > I think it is nice to have.
> >
> > What about only printing the total?
> > With 'wc --total' or 'wc -t'.
>
> Well ` | tail -n1` will always work to get
> the total count irrespective on the number
> of files processed.
>
> I suppose we could support --total={auto,never,always,only} as the interface.
> I'll think about it.

The attached implements this, and operates like:

$ wc --total=only src/wc.c /dev/null
1037 3635 30277

$ wc --total=always src/wc.c
 1037  3635 30277 src/wc.c
 1037  3635 30277 total

$ wc --total=never src/wc.c /dev/null
   1037    3635   30277 src/wc.c
      0       0       0 /dev/null

$ wc --total=auto src/wc.c /dev/null
   1037    3635   30277 src/wc.c
      0       0       0 /dev/null
   1037    3635   30277 total

cheers,
Pádraig

wc--total.patch
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