my ($flag,@lines);

my $d='Dataentry';

sub process {

      push (@lines,"$_[0]\n");
      $flag ||= $_[0]=~ m@>bbbbbb<@s;
        @l ='' if ($_[0]=~m@</$d>@s);

      if (($_[0]=~ m@<$d>@s)&&($flag))
        {
         pop @lines;
         say "<$d>";
         print reverse @lines;
         say "</$d>";
         @lines = '';
         $flag = 0;
        }
      }

process $_ for reverse split '\n';