tos@homer ~/tos/tmp
# cat recip 
#!/usr/bin/perl

use strict;
use warnings;
use IO::Socket;

my $socket=new IO::Socket::INET (LocalPort => 1960,
                              Proto => 'tcp',
                              Listen => 5,
                              Reuse => 1,
                             );
die "could'nt create socket: $!" unless $socket;
while (my $new_socket = $socket->accept()) {
  while (defined (my $buf = <$new_socket>)) {
    print $buf;
         $buf =~ /^ls/ && do { system ("ls") };
  }
}

close ($socket);

##</code><code>##

tos@VRANZ /cygdrive/t/tos/tmp
# cat sndr 
#!/usr/bin/perl

use strict;
use warnings;
use IO::Socket;

my $socket=new IO::Socket::INET (PeerAddr => 'homer',
                              PeerPort => 1960,
                              Proto => 'tcp'
                             );
die "couldn't create socket: $!" unless $socket;

foreach (1..3) {
  print $socket "message $_\n";
  $socket->flush();
}
print $socket "ls\n";
$socket->flush();

close ($socket);

##</code><code>##

tos@VRANZ /cygdrive/t/tos/tmp
# perl sndr

tos@VRANZ /cygdrive/t/tos/tmp
# 

##</code><code>##

tos@homer ~/tos/tmp
# perl recip
message 1
message 2
message 3
ls
recip  sndr  sndr~  x