* NETWORK/PIAF/STAGE FILE [ ACTION OPTION ]

   FILE       C 'file name' D='*'
   ACTION     C 'action' D=' '
   OPTION     C 'Not used'

   Possible OPTION values are:

    N  Not used now, reserved for the future use

   This command provides an interface to the Ntuple backup and staging system.
   The Ntuples are backed up from the stage disks to the STK silo, and can be
   retrieved upon request to the original directory.

   FILE:

         Retrieve an Ntuple file from the STK silo and copy to the spool
         disks of Piaf Server (no wildcards accepted). The file will be copied
         to the original directory from which the file was copied to STK silo.

         If there are more than one file with the same name in the STK silo,
         they will all be retrieved. (These files will be naturally restored
         to different original directiories).

         If the requsted action is 'list' then the file name is used to filter
         the resulting file list. Wildcards '*' and '?' can be used in the file
         name. '*' matches all the characters and '?' matches any single
         character as in UNIX C shell.

   ACTION:  at present the following actions are implemented:

         ' '    - stage the requested file
         'list' - produce a list of files available in the Ntuple archive and
                  indicate which files are not currently on disk.

   WARNING:

         THIS 'STAGE' COMMAND HAS BEEN CHANGED FROM THE ORIGINAL CERN PROGRAM
         PAW, IT IS ONLY VALID INSIDE D0 GROUP AT FERMILAB!!!