WebSocket perl client

gistfile1.pl

#!/usr/bin/perl

use strict;
use warnings;

use POSIX ":sys_wait_h";
use Protocol::WebSocket::Handshake::Client;
use Protocol::WebSocket::Frame;
use IO::Socket;
use open ':utf8';
use open ':std';

$| = 1;

run();

sub run {
  my $s = IO::Socket::INET->new(PeerAddr => '127.0.0.1', PeerPort => 50000, Proto => 'tcp');

  if ($s->connected) {
    my $hc = Protocol::WebSocket::Handshake::Client->new(url => 'ws://127.0.0.1:50000');
    my $parent_pid = $$;
    print $s $hc->to_string;

    if (my $pid = fork()) {
      # parent process
      warn "parent:" . $parent_pid;
      warn "child :" . $pid;
      local @SIG{qw/INT TERM ALRM/} = (sub { client_exit($s); }) x 3;

      while (my $msg = <STDIN>) {
        if (waitpid (-1, WNOHANG)) {
          warn "child($pid) is gone (server is down ?)";
          client_exit($s)
        }
        last unless $msg;
        chomp($msg);

        my $frame = Protocol::WebSocket::Frame->new($msg);
        print $s $frame->to_string;
      }
      # close connection.
      client_exit($s);
    } elsif (defined $pid) {
      # child process
      close STDOUT; close STDIN; close STDERR;
      while (my $l = $s->getline) {
        print $l;
      }
      # send INT signal to parent process.
      kill 2, $parent_pid;
    }
  }
}

sub client_exit {
  my $s = shift;
  if ($s->connected) {
    # close connection
    print $s "\xFF\x00";
    close $s
  }
  if (my $child_pid = wait -1, WNOHANG) {
    kill 9, $child_pid;
  }
  exit;
}