use strict; use warnings; use feature 'say';
use Data::Dumper;

my %results;

while (<DATA>) {
    chomp;
    $results{'zero'}++ if $_ == 0;
    $results{'pos'}++ if $_ > 0;
    $results('neg'}++ if $_ < 0;
}

print Dumper \%results; 

##</code><code>##

if ($num =~ m/  \A (-?) ([0-9]+) \z /x ) {
    my $sign = $1;
    my $digits = $2;
    ...
}