use strict; use Data::Dumper; my %list = ( A => '1.13.04:Record:A', B => '1.12.04:Record:B', C => '3.13.04:Record:C', D => '3.13.02:Record:D', ); my @sorted_date = map { [ $_->[1], $_->[0], $_->[2] ] } sort { $b->[1] <=> $a->[1] } map { my @n = $list{$_} =~ /^(\d+)\.(\d+)\.(\d+):/; my $d = sprintf "%02d%02d%02d", @n[2,0,1]; [join('.',@n), $d, $_] } keys %list; my $month; foreach (@sorted_date) { my $m = substr($_->[0], 0, 4); # retrieve YYMM if ($month ne $m) { print "\n" if $month; $month = $m; print "\n"; } print "\n"; } print "
$_->[1]HASH key: $_->[2]
\n" if $#sorted_date >= 0;