#!/bin/env perl

use IPC::Open2; # for two-way communication via pipe
my @ports = qw /2222 3333/;
my $isRunning = 1;
my $connections = (); # hashref of port connections

# store file handles and pid for each opened port in @ports

foreach $port ( @ports ) {
  local ( *Reader, *Writer );
  my $pid =  open2(\*Reader, \*Writer, "nc -l -p $port\n")
    && print "Opened local port for IO: $port\n";
  $connection->{$port}->{"pid"} = $pid;
  $connection->{$port}->{"Reader"} = *Reader;
  $connection->{$port}->{"Writer"} = *Writer;
}

# Listen to each port and reply to whatever comes in

while ($isRunning){
  foreach $port ( @ports ) {
    my $Reader = $connection->{$port}->{"Reader"};
    my $Writer = $connection->{$port}->{"Writer"};
    if ( $_ = <$Reader> ) {
      print $Writer &readAndFormResponse($port , $_);
    }
  }
}

# Dummy handler

sub readAndFormResponse {
  my $port = shift;
  my $data = shift;
  return "Reply to port: $port\n";
}