It's generally not considered a good idea to manipulate XML with regular expressions - dedicated XML parsing modules tend to do a better job.

That's said, here's one way to do it:

  1 while $text =~ s{
    <names?> ([^<]*) </names?>
    <name>   ([^<]*) </name>
  }{<names>$1,$2</names>}gx;
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This assumes that the 'name' tags cannot contain additional XML entities. It also isn't particularly efficient, but should be fine if your strings aren't longer than a few KB or so.

Hugo