sub daemonize {
    my $childpid;
    
    if(($childpid = fork()) < 0) {
	die("can't fork: $!");
    } elsif($childpid > 0) {
	exit(0);		# parent - exits
    }

    (setpgrp() != -1) || die("Can't change process group: $!");
    
    $SIG{HUP} = 'IGNORE';

    if(($childpid = fork()) < 0) {
	die("can't fork: $!");
    } elsif($childpid > 0) {
	exit(0);		# parent - exits
    }
    
    chdir("/");

    umask(0);
}