0  #!/usr/bin/perl
  1  # file: eliza_server.pl
  2  use Chatbot::Eliza;
  3  use IO::Socket;
  4  use POSIX 'WNOHANG';
    
  5  use constant PORT => 12000;

  6  # signal handler for child die events
  7  $SIG{CHLD} = sub { while ( waitpid(-1,WNOHANG)>0 ) { } };
        
  8  my $listen_socket = IO::Socket::INET->new(LocalPort => PORT,
  9                                           Listen => 20,
 10                                           Proto  => 'tcp',
 11                                           Reuse   => 1);
 12  die "Can't create a listening socket: $@" unless $listen_socket;
 13  warn "Server ready.  Waiting for connections...\n";   
    
 14  while (my $connection = $listen_socket->accept) {
 15      die "Can't fork: $!" unless defined (my $child = fork());
 16      if ($child == 0) {
 17          $listen_socket->close;
 18          interact($connection);
 19          exit 0;
 20      }
 21  } continue {
 22          $connection->close;
 23  }
    
 24  sub interact {
 25      my $sock = shift;
 26      STDIN->fdopen($sock,"r")  || die "Can't reopen STDIN: $!";
 27      STDOUT->fdopen($sock,"w") || die "Can't reopen STDOUT: $!";
 28      STDERR->fdopen($sock,"w") || die "Can't reopen STDERR: $!";
 29      STDOUT->autoflush(1);
 30      Chatbot::Eliza->new->command_interface;
 31  }