foreach($_){ 

##</code><code>##

   my ($num,$date,$time,$fw,$type,$action,$alert,$int,$dir,$proto,$src,$dst,$service,$sport,$len,$rule) = (split /;/,$_);

##</code><code>##

   my (undef, undef, undef, undef, undef, undef, undef, undef, undef, undef, undef, $dst, $service, undef, undef, undef) = split /;/; # split() works on $_ if only one argument is given.

##</code><code>##

   my ($dst, $service) = (split /;/)[11, 12];

##</code><code>##

    %hash = (dest => $dst, service => $service); 
    foreach my $key (keys %hash){
    my $val = $hash{$key};
    $count{$val}++;
    } #close foreach
} #close while

##</code><code>##

    $count{$_}++ for $dst, $service;
}

##</code><code>##

foreach my $key1 (keys %count){
  print "$key1 appears $count{$key1} times\n"; 
} #close foreach 

##</code><code>##

print map "$_ appears $count{$_} times\n", keys %count;

##</code><code>##

#!/usr/bin/perl -w
use strict; 
                                                                          
my $log = './log';   
my %count;
 
open (LOG, $log) or die "Can't open $log: $!"; 
while (<LOG>){
   my ($dst, $service) = (split /;/)[11, 12];
   $count{$_}++ for $dst, $service;
   # Now I see it this way, I realise that
   # $count{$_}++ for (split /;/)[11, 12];
   # would be even better :)
}

print map "$_ appears $count{$_} times\n", keys %count;

##</code><code>##

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$