sub recurse_tree {
    my @dirs = @_;
    my @files;
    for my $dir ( @dirs ) {
        opendir DIR, $dir or error("Can't open $dir\n");
        while ( my $file = readdir DIR ) {
          next if $file eq '.' or $file eq '..';
          next if -l "$dir/$file";
            push @dirs, "$dir/$file" if -d "$dir/$file";
            push @files, "$dir/$file" if -f "$dir/$file";
        }
        closedir DIR;
    }
  return \@dirs, \@files;
}