You could use a negative look behind assertion to do this:

($dum)  = $str =~/(?<!abc).*abc\s(\d+)/gs;

To read more about this feature, along with lots more on regex, check out perlre.

Update: Another way to do this is explained in Roy Johnson's post on look-ahead and look-behind. I knew I had seen this before, but couldn't find it when I was first answering your question.

/abc(?!.*abc)\s(\d+)/s

Not sure which is easiest for you to understand, but either way I would recommend reading that post. (Thanks to prasadbabu for linking to it in a later node so I could find it again!)

In reply to Re: REGEXP: only need last matching string by thedoe
in thread REGEXP: only need last matching string by jeanluca

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