#!/usr/bin/perl
# startup with "scriptname localport redirect"
use warnings;
use strict;
use IO::Socket;

# port to listen on, stuff to write to clients
my ( $localport, $redirect ) = ( $ARGV[0], $ARGV[1] );

# setting up server
my $server = IO::Socket::INET->new(
    LocalPort => $localport,
    Proto => 'tcp',
    Listen => SOMAXCONN,
    Reuse => 1
) || die "couldn't be a tcp server on port $localport:$@\n";

# status
print qq{DAEMON LISTENING ON: $localport\n};

# new connections are instantiated like so
while ( my ($client, $c_addr) = $server->accept()) {

    # collecting details about new connection
    my ($client_port, $c_ip) = sockaddr_in($c_addr);
    my $client_ipnum = inet_ntoa($c_ip);
    my $client_host = gethostbyaddr($c_ip, AF_INET);

    # printing client info
    print qq{INCOMING: $client_host, $client_ipnum\n};

    # retrieving whatever the incoming connection is saying
    while(<$client>) {
        print;
        print $client $redirect;
    }
}