my @wanted;
opendir my $dh, $dir or die "Failed opening $dir: $!";
foreach (readdir $dh) {
    next unless /^tim(\d+)/;
    my $num = $1;
    push @wanted, $_ if $num > 14 and $num < 51;
}
closedir $dh;

##</code><code>##

my @tim_file = do {
    opendir my $dh, $dir or die "Failed opening $dir: $!";
    grep {
        my ($num) = /^tim(\d+)/;
        defined $num and $num > 14 and $num < 51;
    } readdir $dh;
};