!/usr/bin/perl
use strict;
use warnings;
my $file_in='test.txt';
my $file_out='test.out.txt';
my %order;
{
  open(my $fh, '<', $file_in) or die("ERROR open $file_in ($!)\n");
  while(my $line=<$fh>)
  {
    if(my ($name)=$line=~/(\w+)\.xml\.gz/)
    { push(@{$order{$name}},$line); }
  }
  close($fh);
}

my @data;
for my $arr (values(%order))
{
  shift(@$arr) while(@$arr>2);
  push(@data,@$arr);
}

{
  open(my $fh, '>', $file_out) or die("ERROR open $file_out ($!)\n");
  print $fh @data;
  close($fh);
}