Here's a very small IRC-like server example with no frills. Have several windows telnet into its port (or ports, it can handle several), and whatever line one telnet sends gets sent to all the other telnet clients.

#!/usr/bin/perl

use IO::Socket;
use IO::Poll qw( POLLIN POLLOUT );
use strict;
$| = 1;

my $poll = IO::Poll->new;

$poll->mask($_ => POLLIN) for my @listens = map
  {
  IO::Socket::INET->new(LocalPort => $_, Listen => 9, Reuse => 1)
    or die "$@ opening socket on port $_"
  } my @ports  = @ARGV ? @ARGV : (6666);
my %listens = map { $_ => $_ } @listens;

print "ready on @ports...\n";

while(1)
  {
  $poll->poll;
  for my $h ($poll->handles(POLLIN))
    {
    if($listens{$h})
      {
      my $new = $h->accept;
      $poll->mask($new => POLLIN);
      print "accepted from: ", $new->peerhost, ":", $new->peerport, "\
+n";
      }
    elsif(sysread $h, my $in, 1024)
      {
      $listens{$_} or $h == $_ or print $_ $in for $poll->handles;
      }
    else
      {
      $poll->remove($h);
      }
    }
  }
[download]

Thanks a million - it actually helped.. I just used IO::Handle instead of Socket in my particular case:

  6 my $io1 = new IO::Handle;
  7 my $io2 = new IO::Handle;
(...)
 63 open FH307, "/sys/class/gpio/gpio307/value";
 64 open FH308, "/sys/class/gpio/gpio308/value";
 65 
 66 $io1->fdopen(fileno(FH307), "r") || die "Unable to fdopen FH307!!"
+;
 67 $io2->fdopen(fileno(FH308), "r") || die "Unable to fdopen FH307!!"
+;
 68 $poll = IO::Poll->new();

print "With my best wishes: Tomasz\r\n";
 69 
 70 $poll->mask($io1 => POLLPRI | POLLERR);
 71 $poll->mask($io2 => POLLPRI | POLLERR);
[download]