#!/usr/bin/perl
use strict;
use warnings;

my $file = "zipcodes.txt";
my %zipcodes;

open (my $fh, '<', $file) or die "Can't open $file for read: $!";

while (<$fh>) {
  chomp;
  $zipcodes{$_}++;
}

close $fh or die "Cannot close $file: $!";

while (chomp( my $line = <STDIN> )) {
  print "found $line\n" if $zipcodes{ $line };
}
__END__