The fact that something is one line is not relevant. Consider this document as a single line-

It wouldn't make it any easier to parse. In your case, I'm guessing you're resisting a parser because your XML is invalid (aka, garbage). A parser *is* the way to go and if you provide real sample XML you'll probably get help with it. That said, this might do what you want without a parser-

my $doc = '<?xml version="1.0"?><root><a:b>one</a:b><a:b>two</a:b></ro
+ot>';
my $last = [ $doc =~ /a:b>([^<]+)/g ]->[-1];
print $last, $/;
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It won't be reliable or flexible though. :|