use strict;
use warnings;

sub func1 {
  my $nums = shift;
  print("func1: ", join(', ', @$nums), "\n");
  func2($nums);
}

sub func2 {
  my $nums = shift;
  print("func2: ", join(', ', @$nums), "\n");
}

my @nums = (10,400,2,7,20,40,23,100,2);
print("main:  ", join(', ', @nums), "\n");
func1(\@nums);