#!/usr/bin/perl
# file: gab2.pl
# Figure 5.8: A working implementation of a gab client

# usage: gab2.pl [host] [port]
# Forking TCP network client

use strict;
use IO::Socket qw(:DEFAULT :crlf);

my $host = shift or die "Usage: gab2.pl host [port]\n";
my $port = shift || 'echo';

my $socket = IO::Socket::INET->new("$host:$port") or die $@;

my $child = fork();
die "Can't fork: $!" unless  defined $child;

if ($child) {
  $SIG{CHLD} = sub { exit 0 };
  user_to_host($socket);
  $socket->shutdown(1);
  sleep;

} else {
  host_to_user($socket);
  warn "Connection closed by foreign host.\n";
}

sub user_to_host {
  my $s = shift;
  while (<>) {
    chomp;
    print $s $_,CRLF;
  }
}

sub host_to_user {
  my $s = shift;
  $/ = CRLF;
  while (<$s>) {
    chomp;
    print $_,"\n";
  }
}