Vigilando Sockets: Un Servidor Simple

El Programa

pp2@nereida:~/src/perl/Event/server$ cat -n server.pl
  1  #!/usr/bin/perl -w
  2  use strict;
  3  use Event qw(loop unloop);
  4  use IO::Socket;
  5
  6  my $channels;
  7
  8  # make socket
  9  my $socket = IO::Socket::INET->new(Listen => 5, LocalPort => 8080, Reuse => 1);
 10  die "[Fatal] Cannot build initial socket.\n" unless $socket;
 11
 12  # install an initial watcher
 13  Event->io(
 14    fd => $socket,
 15    cb => sub {
 16      my $channel=++$channels;
 17
 18      my $client = $socket->accept;
 19
 20      warn "[Error] Cannot connect to new client.\n" and return unless $client;
 21      $client->autoflush;
 22
 23      Event->io(
 24        fd => $client,
 25        cb => sub {
 26          warn "[Server] Talking on channel $channel.\n";
 27
 28          my $handle = $_[0]->w->fd;
 29          my $line=<$handle>;
 30
 31          $handle->print("[Channel $channel] $line");
 32          warn "Received from $channel: $line";
 33
 34          if ($line=~/^quit\r?$/i) {
 35            $_[0]->w->cancel;
 36            warn "[Server] Closed channel $channel.\n";
 37          }
 38        },
 39      );
 40
 41      $client->print("Welcome, this is channel $channel.\n");
 42
 43      warn "[Server] Opened new channel $channel.\n";
 44    },
 45  );
 46
 47  print "Server process: $$\n";
 48  loop;

Ejecución

Servidor

pp2@nereida:~/src/perl/Event/server$ server.pl
Server process: 8461
[Server] Opened new channel 1.
[Server] Talking on channel 1.
Received from 1: Hola, aqui un cliente
[Server] Opened new channel 2.
[Server] Talking on channel 2.
Received from 2: Soy el cliente lento
[Server] Talking on channel 2.
Received from 2: quit
[Server] Closed channel 2.
[Server] Talking on channel 1.
Received from 1: quit
[Server] Closed channel 1.
Terminado (killed)

Primer Cliente

pp2@nereida:/tmp/Continuity-0.991/eg$ telnet localhost 8080
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Welcome, this is channel 1.
Hola, aqui un cliente
[Channel 1] Hola, aqui un cliente
quit
[Channel 1] quit
Connection closed by foreign host.
pp2@nereida:/tmp/Continuity-0.991/eg$ kill -9 8461
pp2@nereida:/tmp/Continuity-0.991/eg$

Segundo Cliente

pp2@nereida:/tmp$ telnet localhost 8080
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Welcome, this is channel 2.
Soy el cliente lento
[Channel 2] Soy el cliente lento
quit
[Channel 2] quit
Connection closed by foreign host.
pp2@nereida:/tmp$

Véase También

Para saber mas sobre sockets y el módulo IO::Socket véase la sección 13.5.