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Date: Thu, 7 Dec 2017 01:19:48 +0000
From: RW <rwmaillists@googlemail.com>
To: freebsd-questions@freebsd.org
Subject: Re: grep problem
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On Thu, 7 Dec 2017 00:55:42 +0000
RW 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]...


Never mind, the shell handles the quotes, so grep sees -b as an option
rather than a pattern.