GNU bug report logs - #37607
How to use Grep with Using -o

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Matt Zand <mahdiumd <at> gmail.com>
To: bug-grep <at> gnu.org
Subject: How to use Grep with Using -o
Date: Thu, 3 Oct 2019 11:54:24 -0400

[Message part 1 (text/plain, inline)]

Hi,

Is it possible to output symbols which constitute non-matched parts of
text? For instance, I expect

printf "banana\napple" | grep --invert-match --only-matching 'ban'

to produce

ana
apple

or

apple

, but it doesn't produce anything.

I need -o because I grep multiline pattern with -z.




-- 
Cheers,

Matt Zand
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Message #8 received at 37607 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Matt Zand <mahdiumd <at> gmail.com>, 37607 <at> debbugs.gnu.org
Subject: Re: bug#37607: How to use Grep with Using -o
Date: Thu, 2 Jan 2020 02:00:41 -0800

On 10/3/19 8:54 AM, Matt Zand wrote:

> Is it possible to output symbols which constitute non-matched parts of
> text? For instance, I expect
> 
> printf "banana\napple" | grep --invert-match --only-matching 'ban'
> 
> to produce
> 
> ana
> apple
> 
> or
> 
> apple
> 
> , but it doesn't produce anything.

Unfortunately the -v and -o options don't currently combine in that way. Perhaps
they should, or perhaps another option could be added to do what you want. I'll
mark this as a wishlist item.

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