Re: [bug #34917] grep refuses to run when input file is also the output, even when the -q option is used

[nicolas vigier]

On Mon, 28 Nov 2011, Jim Meyering wrote:

> Nicolas Vigier wrote:
> > Follow-up Comment #1, bug #34917 (project grep):
> >
> > Oops, I misunderstood the issue reported on Mageia bugzilla.
> >
> > The issue is a little different :
> > When the -q option is used, there should not be any error output. grep 
> > version
> > 2.10 outputs errors about "input file `./file' is also the output" even when
> > the -q options is used.
> >
> > But not rejecting the command when the -q option is used should also fix 
> > this.
> 
> Thanks for forwarding that and for the patch.
> I've added a comment and a proper commit log to your patch, but
> that means you'll have to sign off on the grammar/etc. before I push.
> Please reply here, and not on the savannah tracker.

This looks good. Thanks.

> 
> I'll update NEWS and add a test separately.
> 
> Note that using -q and redirecting stdout is slightly nonsensical,
> since you know there will be no standard output.

I agree that it does not make a lot of sense to redirect output of grep -q,
however I think it's possible to use grep -q inside a longer script whose
output is redirected to a file, redirecting the output of grep -q at the
same time.