use POSIX qw/setsid/;
sub daemonise
{
    my ($self) = @_;
    chdir('/') or die "Can't chdir to /: $!";
    open STDIN, "</dev/null";
    defined(my $pid = fork) or die "Can't fork: $!";
    exit if $pid;
    setsid();
    $SIG{HUP} = \&hup_handler($self); # you need to define this
   # we store our pid's for shutdown
    if ( $self->{pidfile} ) {
     open PIDFILE, "> " . $self->{pidfile};
     print PIDFILE "$$\n";
     close PIDFILE;
    }
}