Date: Mon, 10 Aug 2020 16:49:24 +0200 From: Polytropon <freebsd@edvax.de> To: Robert Huff <roberthuff@rcn.com> Cc: Ernie Luzar <luzar722@gmail.com>, "freebsd-questions\@freebsd.org" <freebsd-questions@freebsd.org> Subject: Re: csh use of grep | tr commands Message-ID: <20200810164924.4ec11e74.freebsd@edvax.de> In-Reply-To: <24368.41568.96908.196223@jerusalem.litteratus.org> References: <5F30962B.5060005@gmail.com> <24368.41568.96908.196223@jerusalem.litteratus.org>
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On Sun, 9 Aug 2020 21:26:56 -0400, Robert Huff wrote:
> Ernie Luzar writes:
>
> > Double quotes are giving me trouble.
> >
> > I have a file with a line in it like this
> > ip4="10.111.098.2"
> > I want to get just the ip address
> >
> > ip=`grep "ip4=" directory-path/file-name
> >
> > $ip ends up having ip4="10.111.098.2" in it
> >
> > ip=`echo -n "${ip}" | tr -d "ip4="
> >
> > $ip ends up having "10.111.098.2" in it
> >
> > Putting | tr """ " "` after the echo above gives error.
> >
> > How do I remove the " around the ip address?
>
> Would awk perhaps be a better tool?
Possibly. But it's more elaborate than sed. :-)
% echo 'ip4="10.111.098.2"' | awk '/^ip4=/ { gsub("ip4=", "", $0); gsub("\"", "", $0); print $0 }'
10.111.098.2
Compared to:
% echo 'ip4="10.111.098.2"' | sed 's/ip4="//g; s/"//g'
10.111.098.2
However, awk can eliminate a possible grep invocation to
only process matching lines, which might be an advantage.
--
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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