Date: Thu, 7 Dec 2017 01:08:01 +0000 From: Ken Moffat <zarniwhoop@ntlworld.com> To: RW <rwmaillists@googlemail.com> Cc: freebsd-questions@freebsd.org Subject: Re: grep problem Message-ID: <20171207010801.GA10604@milliways.localdomain> In-Reply-To: <20171207005542.43a7f55f@gumby.homeunix.com> References: <20171207005542.43a7f55f@gumby.homeunix.com>
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On Thu, Dec 07, 2017 at 12:55:42AM +0000, RW via freebsd-questions wrote:
>
> Can anyone explain why '-' needs escaping in the following. What
> special meaning does it have outside of []?
>
> $ echo 'a-b' | grep 'a-b'
> a-b
>
> $ echo 'a-b' | grep '-b'
> Usage: grep [OPTION]... PATTERN [FILE]...
> Try `grep --help' for more information.
>
> $ echo 'a-b' | grep '\-b'
> a-b
>
In gnu grep, '-' indicates it should read from STDIN, I assume that
FreeBSD's grep is the same.
ĸen
--
Truth, in front of her huge walk-in wardrobe, selected black leather
boots with stiletto heels for such a barefaced truth.
- Unseen Academicals
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