getpid function returns the process id (pid) of the
Vortex process running the script. This may be used to identify a
process among multiple simultaneous Vortex invocations.
getpid function returns the integer Vortex process ID.
getpid function was added in version 2.1.900900000 19980720.
Although a process id is unique among currently-running processes, it may be re-used eventually once a process exits.