* If:

** file path does not start with / it's taken to be relative to /var/run/ (i.e. named/named.pid -> /var/run/named/named.pid)

** no pid file path specified, then the pid file is assume to be /var/run/<name>.pid

** does not exist, otherwise the platform will do a pgrep <name>

** returns something, it's assumed it will be valid PIDs for that service

* not that this is not recommended as pgrep may pick up other processes running by a name containing <name>, e.g., ssh-agent