One simple thing you could do is just build your own pacing code around something like XML::Simple :

use strict;
use XML::Simple;
use Data::Dumper;

while (<>) {

  next if /xml|ArgusDataStream/;
  my $xml=$_;
  $xml.=<> while $xml !~ m|</ArgusFlowRecord>|;
  my $xmlhash=XMLin($xml);
  print Dumper($xmlhash);  
  
}
__END__
$ xmlstuff.pl <xmlinput
$VAR1='
   Flow data set 1
';
$VAR1='
   Flow data set 2
';
[download]

where the file xmlinput contained:

<?xml version="1.0">
<ArgusDataStream>
<ArgusFlowRecord>
Flow data set 1
</ArgusFlowRecord>
<ArgusFlowRecord>
Flow data set 2
</ArgusFlowRecord>
</ArgusDataStream>
[download]

Your XML processing will of course be completely different (and probably not use XML::Simple), but this should give you an idea on how to proceed.

Update: this is basically the same as marcello's solution, and is probably better handled with an event based parser such as XML::Sax::PurePerl, as per jeffa's suggestion in the chatterbox.

CU
Robartes-