You could extend F::CF to support zeroing out the counter.

Something like...

package File::CounterFile::Resettable;

use base qw( File::CounterFile );

sub reset
{
    my($self) = @_;

    if ($self->locked) {
        $self->{'value'} = 0;
        $self->{updated} = 1;
    } else {
        $self->lock;
        $self->{'value'} = 0;
        $self->{updated} = 1;
        $self->unlock;
    }
    $self->{'value'}; # return value
}
[download]

...and then later in your script...

my $count = File::CounterFile::Resettable->new("./asr_counter.txt");
$count->lock();
$count->reset();
$count->unlock();
[download]

(Code is untested, but you hopefully get the idea!) Update: $code =~ s/\t/ /g; # for readability.