Date: Thu, 17 Jan 2002 03:56:50 +0100 From: Erik Trulsson <ertr1013@student.uu.se> To: Drew Tomlinson <drew@mykitchentable.net> Cc: questions@freebsd.org Subject: Re: Regular Expression Syntax Message-ID: <20020117025650.GA83411@student.uu.se> In-Reply-To: <000b01c19f00$d396db20$0301a8c0@bigdaddy> References: <000b01c19f00$d396db20$0301a8c0@bigdaddy>
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On Wed, Jan 16, 2002 at 06:44:04PM -0800, Drew Tomlinson wrote:
> I've been beating my head and just can get the syntax of this right.
> This expression works:
>
> blacklamb> pkg_info | egrep "portupgrade|cvsup" | awk '{print
> "pkg_deinstall " $1}'
> pkg_deinstall cvsup-16.1_3
> pkg_deinstall portupgrade-20011210
>
> How can I get the opposite? In other words, everything except cvsup
> or portupgrade? I know about the ! and () for grouping but can't seem
> to get it in the right place. Help.
I don't think the version of regular expressions used by [e]grep
supports any negation operator. Regular expressions in general do not
have any "not" operator defined. Some extended variants of regular
expressions (like that found in Perl which is so extended that it
actually no longer qualifies as 'regular' :-) ) does support that.
Now, for your problem there is a much easier solution. Use the '-v'
option for egrep.
Quoting from the manpage for egrep(1):
-v, --invert-match
Invert the sense of matching, to select non-match-
ing lines.
--
<Insert your favourite quote here.>
Erik Trulsson
ertr1013@student.uu.se
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