server config, <Global>
1.2.0rc2 and later
The PidFile directive sets the file to which the server records the process id of the daemon. The filename should be relative to the system root, ie /var/run/proftpd/pidfile. The PidFile is only used in standalone mode. It is often useful to be able to send the server a signal, so that it closes and then reopens its ErrorLog and TransferLog, and re-reads its configuration files. This is done by sending a SIGHUP (kill -1) signal to the process id of the master daemon listed in the PidFile.