                                                            BLKALC.LIT


          FUNCTION:


               To  determine  the  current  file allocation of a particular
          block on the specified device.


          HINTS/RESTRICTIONS:


               BLKALC may be run from any account on the  system  and  will
          function for any device on the system.


               BLKALC  does  not  require  the  bitmap to be intact for the
          device; however, the file directory system must be intact.


          FORMAT:


               .BLKALC {device:}{block}{switches}


               The device may be any device that the driver is resident for
          and is currently on the system. Multiple digit drive numbers  are
          permitted.


               Block is the number of the block you wish to search for. The
          entry  may  be  in  either  hex or octal depending on the current
          SETting. A hex block number must start with a numeric  character.
          For  example  block  F43  must  be  entered as 0F43. If the block
          number entry does not agree with the current SETting for  hex  or
          octal, the input block number will be incorrect.


          DEFAULTS:


               If  no  device is specified, then BLKALC will default to the
          device you are currently logged into.


               If no block number is entered on the  command  line,  BLKALC
          will return and ask you the block you wish to search.


          OPTIONS:


               You  may  request BLKALC to look in only a specified account
          by using the /P switch on the command line. If you know,  from  a
          DSKANA  that there is a faulty block but you don't know the file,
          then you can search just the PPN where the  error  occurred.  The
          format is /P:[p,pn]


                                     1
               BLKALC  will  tell you it is searching the specified PPN and
          will return the file or that the block was not associated with  a
          file in the specified PPN.


          OPERATION:

               1.  Type  BLKALC followed by the device and block number you
                   wish to search for.

               2.  BLKALC will  determine  the  number  of  blocks  on  the
                   specified  device  and return this number to the screen.
                   If the block number entered is to large for  the  device
                   BLKALC will return:


                        ?Block  number  specified  is  too  large  for this
                   device.



               3.  BLKALC will then determine if the block specified  is  a
                   part of the bitmap or the Master File Directory (MFD).

               4.  Finally,  BLKALC  will  begin  to search the entire file
                   structure of the device using the Master File  Directory
                   and all the User File Directories to search each file to
                   determine  the specified block's allocation. BLKALC will
                   return a <.> to the screen as it reads  each  UFD  entry
                   and  checks  the  associated  file.  A deleted file will
                   result in a <.> being  displayed;  however,  no  further
                   searching  will  occur. To remove deleted files from the
                   UFD you should run DIRSEQ as  described  in  the  System
                   Commands Reference Manual.

               5.  Upon finding the specified block, BLKALC will return the
                   file specification and return to AMOSL.

               6.  If  the  block  is  not found after searching the entire
                   file directory system, it is assumed the  block  is  not
                   allocated and the system will return:


                        Block #____ has not been allocated!



          ERRORS:

               A.  ^specification error:

                        Your  command  line  was of incorrect format. The ^
                   points to the location that BLKALC does not understand.

               B.  ?Block number too large for this device.

                        The number you have  entered  is  larger  than  the
                   number of blocks on the specified, or default device.



                                     2
               C.  ?Block number specified is a negative octal number

                        The  number  you have entered equates to a negative
                   octal number. Check the block and try again.

               D.  All other error messages are from AMOSL operating system



          CHARACTERISTICS:


               You can use BLKALC to determine the current file  allocation
          of any block on any mounted device.


               BLKALC is both re-entrant and reusable.


               BLKALC  is  control C (^C) interruptable, if CTRLC is SET on
          the user's terminal.


          EXAMPLES:


               .BLKALC

               Block allocation search has been initiated on: DSK0
               Enter the block number to be searched: 13
               Block number to be searched: 13
               ...
               Block # 13 has been found in the User File Directory DSK0:[1,2]



               .BLKALC DSK1: 13

               Block allocation search has been initiated on: DSK1
               Block number to be searched: 13
               ....
               Block # 13 has been found in the User File Directory DSK1:[1,2]



               .BLKALC DSK1: 0

               Block allocation search has been initiated on: DSK1
               Block number to be searched: 0
               Block zero is the device label block.





                                        BLKALC.LIT was written by:
                                        Quaker State Oil Refining Corp.
                                        Research Center
                                        Oil City, PA  16301 - March 1984


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