You are welcome.

OK, now I understand why you're using an arrayref with references to the counters. Although I guess a simple array with references to the counters would also work.

An alternative approach would be to build dynamically the output subroutine depending on your input:

#!/usr/bin/perl
use warnings;
use strict;

my $verbose = shift // 0;
my $excluded = 2;
my $count = 42;
my $completed = 6;
my $notify_progress = build_output_subroutine(); 

$notify_progress->();
$completed = 7;
$notify_progress->();

sub build_output_subroutine {
    my @out;
    if ($verbose) {
        return sub  { print "Processing: ",  $count, " files to proces
+s ; ", $excluded, " files excluded; ", $completed, " files completed\
+n" };
    } else {
        return sub { print "Processing: ",  $count, " files to process
+ ; ", $completed, " files completed\n" };
    }
}
[download]

But, in this context, this probably does not really make things really simpler.