NAME
       pid - Retrieve process id(s)

SYNOPSIS
       pid ?fileId?


DESCRIPTION
       If  the  fileId  argument is given then it should normally
       refer to a process pipeline created with the open command.
       In this case the pid command will return a list whose ele
       ments are the process identifiers of all the processes  in
       the  pipeline, in order.  The list will be empty if fileId
       refers to an open file that isn't a process pipeline.   If
       no  fileId  argument is given then pid returns the process
       identifier of the current process.   All  process  identi
       fiers are returned as decimal strings.


KEYWORDS
