use strict;
use warnings;

my $ips      = 'ip.dat';
my $in_data  = 'DJB.dat';
my $out_data = 'DJB_new.dat';
my %ip_map;

# you should ask for a shared lock in case someone updates this
open IPS, "< $ips" or die "Couldn't open $ips for reading: $!";

while ( <IPS> ) {
    my ( $ip, $name ) = split /:/, $_, 2;
    warn "$ip is already mapped to $ip_map{$ip }" if exists $ip_map{ $ip };
	chomp $name;
    $ip_map{ $ip } = $name;
}

close IPS;

open IN_DATA, "< $in_data"   or die "Couldn't open $in_data for reading: $!";
open OUT_DATA, "> $out_data" or die "Couldn't open $out_data for writing: $!";

while ( <IN_DATA> ) {
	my $replace;
	my $ip = '';
    ( $replace, $ip ) = ( /^\+([^:]+):([\d.]+)/ );
	if ( exists $ip_map{ $ip } ) {
		s/$replace/$ip_map{ $ip }/;
	}
	print OUT_DATA $_;
}

close OUT_DATA;
close IN_DATA;