1 use Data::Dumper;
  2 use feature 'say';
  3
  4 my $hashref;
  5 my $code;
  6 while(my $line = <DATA>) {
  7     chomp $line;
  8     my @pieces = split ':',$line;
  9     my $val = pop @pieces;
 10     $code .= ('$hashref'.join '',map { "->{'$_'}" }@pieces)."='$val';\n";
 11 };
 12 eval $code;
 13
 14 print Dumper $hashref;
 15
 16 __DATA__
 17 globalkey:key2:key3:key4:ARRAY VALUE
 18 globalkey:key2:key3:key4:key5:ARRAY VALUE
 19 globalkey:key2:key3:key4:key5:any arbitrary number of keys:ARRAY VALUE

$VAR1 = {
          'globalkey' => {
                           'key2' => {
                                       'key3' => {
                                                   'key4' => 'ARRAY VALUE'
                                                 }
                                     }
                         }
        };