$SIG{HUP}  = sub {
  if (defined $log)
  {
    undef $log;
  }

  $log = IO::File->new(LOGFILE, 'w');
  $log->print(strftime("%m/%d/%Y %H:%M:%S", localtime),": Caught HUP, reset logfile\n");
  $log->print("pid = $$\n");
  $log->autoflush(1);
};

##</code><code>##

#!/usr/bin/perl

$SIG{HUP}  = sub {
  print "got hup\n";
};

while (1)
{
  print "sleeping\n";
  sleep(1);
}