From: Jano Svitok <jan.svitok@...>
Date: 2007-08-14T04:08:58+09:00
Subject: Re: confused by back refs in gsub

On 8/13/07, Peter Bailey <pbailey@bna.com> wrote:
> Can someone tell me why, in my code below, I'm getting part of the
> original search in my substitution in my result, when, I'm not asking
> for it, or at least, I don't think I'm asking for it.
>
> Thanks,
> Peter
>
>
> Original line:
> <registrantName>Normandy Group LLC</registrantName>
>
> My Code:
> xmlfile.gsub!(/<registrantName>(.*)<\/registrantName>/,
> '<SUB.HEAD4>\&</SUB.HEAD4>')
> I've tried "\1" instead of "\&," too. Same result. I've also tried
> putting in "?" marks to make it non-greedy. Same result.
>
> Yields:
> <SUB.HEAD4><registrantName>Normandy Group
> LLC</registrantName></SUB.HEAD4>
>
> What I want:
> <SUB.HEAD4>Normandy Group LLC(/SUB.HEAD4>

This works for me (I've used \1):

require 'test/unit'
class TestGsub < Test::Unit::TestCase
        def test_replace
                line = "<registrantName>Normandy Group LLC</registrantName>"

line.gsub!(/<registrantName>(.*)<\/registrantName>/,'<SUB.HEAD4>\1</SUB.HEAD4>')
                assert_equal(line, '<SUB.HEAD4>Normandy Group LLC</SUB.HEAD4>')
        end
end

Note that you have (/SUB.HEAD4> instead of </SUB.HEAD4> (the parenthesis)