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

open DATA,    "data.txt" or die("Can't open file for reading: $1");
open EXCLUDE, "exclude.txt" or die("Can't open file for reading: $1");
open OUT,     ">out.txt" or die("Can't open file for writing: $1");


my $exclude_serial = <EXCLUDE>; chomp($exclude_serial);
my $line_data = <DATA>;

while ($line_data) {
    chomp($line_data);
    my ($serial, $name, $flag) = split /,/, $line_data;

    # if we've run out of numbers to exclude just print the line to the outfile
    if (! defined $exclude_serial) {
        print OUT "$line_data\n";

    # if we've not yet reached the serial to exclude, again just print the line
    } elsif  ($serial < $exclude_serial) {
        print OUT "$line_data\n";

    # we must need a new exclude number then, pull it off the file, keeping track
    # of whether the current or subsequently read exclude serials mean we shouldn't
    # print the current line
    } else {
        my $write_current_line = 1; # assume it's okay unless we find a match

        do {
            $write_current_line = 0 if $exclude_serial == $serial;
            $exclude_serial = <EXCLUDE>;
            chomp($exclude_serial) if defined $exclude_serial;
        } until (! defined $exclude_serial or ($exclude_serial > $serial) );
        
        print OUT "$line_data\n" if $write_current_line;
    }

    $line_data = <DATA>;
}