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
       elements 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 identifiers are returned as decimal strings.


KEYWORDS
