$b{$readID} || []

##</code><code>##

my %b;

open(B, "<" . DUMP_B) || die("Could not open file \n");
while (<B>) {
  chomp;
  my ($id, $ac) = split /\|/, $_;
  push @{$b{$id}}, $ac;
}

open( OUTPUT, '>', 'INACTIVE_LIST' ) || die "Could not write to file\n";
open(A, "<" . DUMP_A) || die("Could not open file \n");
while(<A>) {
  chomp;
  s/\s+//g;
  if ($b{$_}) {
    for my $ac (@{$b{$_}}) {
      print OUTPUT "$_|$ac\n"
    }
  }
}