#!/opt/local/bin/perl5.10.0
use 5.010;
use strict;
use warnings;

use constant {
  EXCLUDE_TXT => '2.txt',
  DATA_TXT => '1.txt'
};

my %exclude = do {
  open my $in, '<', EXCLUDE_TXT or die "Cannot open exclusion list: $!";
  my $_; map { chomp; $_ => 1 } <$in>;
};

do {
  open my $in, '<', DATA_TXT or die "Cannot open data file: $!";
  while (my $_ = <$in>) {
    my $flop;
    print if (
      (/^xxx(\d{8})/ && !$exclude{$1})
      ...
      ($flop = (/^xxx(\d{8})/ && $exclude{$1}))
      and !$flop
    );
  }
}