Requires SYSPRV (system privilege) or BYPASS privileges to list
    read-protected files.

    Displays a list of the names of all files open on a volume and
    their associated process name and process identification (PID).
    The specified device must be a mounted Files-11 volume. If the
    specified volume is a multivolume set, the files on each volume
    in the set are listed.

                                   NOTE

       The SHOW DEVICES/FILES command does not support defaults
       for nonspecified portions of device names. You must supply
       a complete device specification when using the /FILES
       qualifier.

    If the /SYSTEM qualifier is also specified, only the names of
    installed files and files opened by the system are displayed.
    Files opened by the system are those that have been opened
    without the use of an ancillary control process (ACP), such
    as INDEXF.SYS and QUOTA.SYS, as well as system files such as
    JBCSYSQUE.EXE and SYSMSG.EXE.

    If the /NOSYSTEM qualifier is specified, only those files opened
    by processes are displayed. To list files opened by a process in
    your group, your process must have at least GROUP privilege. If
    the process is not in your group, you need WORLD privilege.

    If neither the /SYSTEM nor the /NOSYSTEM qualifier is specified,
    the names of all files currently opened on the system are
    displayed.

    If a file is read-protected from your user identification code
    (UIC), the "No privilege" message is displayed instead of the
    file name. You must have SYSPRV (system privilege) privilege or
    BYPASS privilege to display the file name.

    A space in place of a file name represents a work file (such as
    a temporary edit file) not entered in any directory. To display
    temporary file names, you must have BYPASS privilege in addition
    to GROUP or WORLD privilege.

    Do not use the /FILES qualifier with the /ALLOCATED, /BRIEF,
    /FULL, or /MOUNTED qualifier. The functions of the /FILES
    qualifier and these qualifiers are mutually exclusive.