my %filenames =();
foreach( <post*.*> ) {
    $filenames{$_} = -M $_;
}

##</code><code>##

my @sorted_keys = sort { $filenames{$a} <=> $filenames{$b}} keys %filenames;

##</code><code>##

foreach my $filename ( @filenames ) {
    # create an ANONYMOUS array (basically a reference to an array)
    my $record = [ $filename, -M $filename ];
    push @filesanddates, $record;
}