/sys$common/syshlp/helplib.hlb Lexicals, F$GETJPI, Example  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  $ NAME = F$GETJPI("3B0018","USERNAME")
  $ SHOW SYMBOL NAME
    NAME = "JANE        "

      This example shows how to use the F$GETJPI function to return
      the user name for the process number 3B0018. The user name is
      assigned to the symbol NAME.