my %count, %hash;

while (<FILE>){
 
 next unless /something/; 
 if (/<LONG REGEX>/){
   
   $hash{$3} = {
        sig => $1,
        src => $3,
        proto => $2,
        dst => $4,
        port => $5,
   };
 
  if ($hash{$3}{src}){
    $count{$3}++;
  }
 }
}