{ # temporarily change Net::Cmd::debug_print
  my $log_buffer;

  local *Net::Cmd::debug_print = sub {
           my ($self, $dir, $text) = @_;
           $log_buffer .= ($dir ? 'snd --> ' : 'rcv <-- ') . $text;
        };

  my $ftp = Net::FTP->new($_[0], Debug => 1) or die "Cannot connect to $_[0]";
  ...
  $ftp->quit;

  print "Log:\n$log_buffer\n";
} # recovers previous behaviour of Net::Cmd::debug_print