I would be interested in a POSIX 1003.2 regular expression (the ones
supported by the GNU regex package) such that it matches anything but a
fixed sequence of characters. My understanding is that

[^abc]

will match anything but any of a, b or c. That is, it will not match e.g.
bca. What I am after is a regular expression such that it would match
anything but exactly the abc sequence.

Any suggestions?

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In article <pan.2004.09.29.17.12.16.814035@story.net>, "Augustus S.F.X Van Dusen" <asfxvd@st
ory.net> writes:
> 	I would be interested in a POSIX 1003.2 regular expression (the ones
> supported by the GNU regex package) such that it matches anything but a
> fixed sequence of characters. My understanding is that
>
> 	[^abc]
>
> will match anything but any of a, b or c. That is, it will not match e.g.
> bca. What I am after is a regular expression such that it would match
> anything but exactly the abc sequence.
>
> 	Any suggestions?
>

Wouldnt it be much simpler to search for 'abc' and negate it?
Such as
grep -v abc
or
sed '/abc/d'
or
awk '!/abc/{print $0}'

--
Michael Tosch
IT Specialist
HP Managed Services
Technology Solutions Group
Hewlett-Packard GmbH
Phone: +49 2407 575 313
Mail: michael.tosch:hp.com

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On Wed, 29 Sep 2004 17:31:22 +0000, Michael Tosch wrote:


> Wouldnt it be much simpler to search for 'abc' and negate it?

It would but, alas, I am using the regex API directly, not via a command
line utility.

> Such as
> grep -v abc
> or
> sed '/abc/d'
> or
> awk '!/abc/{print $0}'

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Augustus S.F.X Van Dusen <asfxvd@story.net> wrote:
> On Wed, 29 Sep 2004 17:31:22 +0000, Michael Tosch wrote:
>
> 
>
>         It would but, alas, I am using the regex API directly, not via
>         a command line utility.

Try
([^a]..|.[^b].|..[^c])
--
William Park <opengeometry@yahoo.ca>
Open Geometry Consulting, Toronto, Canada

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On Wed, 29 Sep 2004 18:10:12 +0000, William Park wrote:

> Augustus S.F.X Van Dusen <asfxvd@story.net> wrote: 
>
> Try
>     ([^a]..|.[^b].|..[^c])

Thanks. The generalization to more characters is a bit awkward,
unfortunately. But, thanks again.

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grep -v abc
is
grep '^([^a]|a([^b]|$)|ab([^c]|$))*$'

Regards
Laurent

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2004-09-30, 05:20(-07), Laurent Schneider:
> grep -v abc
> is
> grep '^([^a]|a([^b]|$)|ab([^c]|$))*$'
[...]

No.

$ echo aabc | egrep '^([^a]|a([^b]|$)|ab([^c]|$))*$'
aabc
$ echo aabc | egrep -v abc
$


^([^a]|a*a[^ab]|[ab]*b(a*a[^ab]|[^ac]))*[ab]*$

Should be better. See
http://groups.google.com/groups?sel...f
ree.fr

--
Stephane

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and
grep -v ^abc$
is
grep '^($|[^a].*|a([^b].*|$)|ab([^c].*|c.|$))$'

PS: grep -E on my system

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2004-09-30, 05:32(-07), Laurent Schneider:
> and
> grep -v ^abc$
> is
> grep '^($|[^a].*|a([^b].*|$)|ab([^c].*|c.|$))$'
[...]

or

grep -E '^([^a]|.[^b]|..[^c]|.{4,}|.{0,2})$'

should work with more versions of egrep (some don't like the "$"
not in last place).

--
Stephane

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2004-09-30, 13:00(+00), Stephane CHAZELAS:
[...]
> grep -E '^([^a]|.[^b]|..[^c]|.{4,}|.{0,2})$'
[...]

Forget it.

grep -E '^(([^a]|.[^b]|..[^c]).*)|.{4,}|.{0,2})$'

--
Stephane

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