I would ask for more details, you've only shown us sample data. If, for example, everything follows your sample in only allowing us to omit end-tags on single-line tags with no embedded tags, then a simple regex (to add end-tags where they are missing) will turn this into real XML and you can come to a real solution. If it's not a huge amount of data, you can just import the string into memory, transfrom it into real XML and then use one of the XML or DBI related modules or whatever modules to query it.

Of course, in the long run, you're better off having whatever produces the data make it real XML to begin with, but in the meantime, this solution should work.