########################################
print 'raw  cu1:'.$cu1."\n"; 
print 'size cu1:'.scalar(@{$cu1})."\n"; 
print 'cu1     :'.join('|',@{$cu1})."\n"; 
########################################
[download]

Raksha Jalan: Rather than using print statements in this way, I would recommend the use of something like Data::Dumper (which is core). It will IMHO be much more informative about what the variable (e.g., $cu1) really is, and will avoid the generation of a bunch more warnings if the variable is undefined.

c:\@Work\Perl\monks>perl -wMstrict -le
"use Data::Dumper;
 ;;
 my $x;
 print Dumper $x;
 ;;
 $x = [];
 print Dumper $x;
 ;;
 $x = [ 'hi', 'there' ];
 print Dumper $x;
"
$VAR1 = undef;

$VAR1 = [];

$VAR1 = [
          'hi',
          'there'
        ];
[download]

BTW: I prefer the Data::Dump module, but it isn't core.