You aren't passing anything into the sub csv

my @array = ( 1, 2, 3, 4, 5 );
csv( @array ); # pass array into csv

sub csv { 
  my @passed_array = @_; # reteive array from @_
  foreach (@array) {
    print "$_\n";
  }
}
[download]

Check out perlsub

Also:
Please reduce your question to the smallest example of your problem. This not only saves us from having to dig through irrelevant code to find your real problem, but a good portion of the time you'll answer it yourself.

Update: added Also section