# first populate array with zipcodes from zipcodes
# text file. 
# --- No problem here

my $file = "zipcodes.txt";
open (FH, "< $file") or die "Can't open $file for read: $!";

my @zipcodes;

while (<FH>) {

    push (@zipcodes, $_);
    	
}

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

# open the text file for processing looking only for
# lines of text with a zipcode from the array @zipcodes
# --- here is the problem as it outputs nothing

while (my $line = <STDIN>) {

	foreach my $zipcode (@zipcodes) { 

        	 if ($line =~ m/$zipcode/) { 
			print $line; 
		}  
	} 
}