The propertyset type has a negate attribute. maybe that will help you.
http://ant.apache.org/manual/Types/propertyset.html



________________________________
From: Steve Amerige <Steve.Amerige@sas.com>
To: Ant Users List <user@ant.apache.org>
Sent: Thursday, November 10, 2011 4:50 AM
Subject: Re: Negative Lookahead and Regexp

Hi all,

So, I'm guessing that Ant 1.7+ (with optional Ant-Contrib) doesn't support negative lookahead regex searches.

So, I'm refocusing on the main objective here: I want a propertyset that excludes properties matching certain patterns.  Any idea as 
to how to accomplish this?

Thanks!
Steve Amerige
SAS Institute, Deployment Software Development

On 11/9/2011 3:40 PM, Steve Amerige wrote:
> Hi all,
>
> Is negative lookahead supported at all in Ant 1.7 and higher (Ant-Contrib, too)?  Maybe my syntax is off:
>
> <propertyregex property="result" input="a.b.c.bad" select="\1" regexp="(.*(?!bad))" defaultValue="" override="true"/>
> <propertyregex property="result" input="a.b.c.ok" select="\1" regexp="(.*(?!bad))" defaultValue="" override="true"/>
>
> The first result should be the empty string and the second result should be "a.b.c.ok".  I'm also looking to use this idea in 
> <propertyset> to exclude certain properties.
>
> See the regular expression page on this:
>
> http://www.regular-expressions.info/lookaround.html