How to Create Sequential Files Views.

Introduction:

You can create SAM views with varying degrees of access restrictions. There are three categories of views: Shell, VTOC and specific. Shell views are the least restrictive while Specific views are the most restrictive case. VTOC views are in-between.

Shell views:      No restrictions. The user can point the view to any data set he chooses!
VTOC views:   Restrict access to a set of sequential files on one DASD Volume.
Specific views: Restrict the client to one sequential file. The server, however, might point the
                               view to different files at different times if the admin codes variables in the
                               data set name.

SAM Shell, or Generic, Views:

The user can point a shell view to any data set he chooses! Therefore, access to shell views should be restricted to trusted users, if at all.

The following example shows how to create a shell view. The coded statements are absolutely required. The two links provide more information about other statements you may have to code as well.

Please notice that the user can transform this view into a Specific
Managed-SAM, DISK-SAM or TAPE SAM view.

VTOC Views:

VTOC Views grant access to a set of SAM files on one DASD volume. The admin can use the MASK statement, in the user's PROF, to limit the user to a subset of files. The user can list the VTOC and may FTP any visible data set. With the aide of a DASD space manager, the user can even create new data sets as well.

The following example shows how to create a VTOC view. The coded statements are absolutely required. The two links provide more information about other statements you may have to code as well.

SAM Specific Views:

Each SAM Specific view grants access to one sequential data set. The user can't point the view to other data sets. But the server can if the admin codes
in the data set name. However, it should be noted that "the collection" of files the view points to must have identical attributes (i.e., same recformat, reclen, ..etc).

There are three types of SAM specific views:

1. Managed-SAM
2. DISK-SAM
3. TAPE-SAM.

1. Managed-SAM (SAM in VSAM space) Specific Views:

       To correctly code a managed-SAM specific view, you must code all relevent data set attributes
         required by the FTP server in order to read and write the data set. For more information about
         managed-SAM data set attributes, please click here.

         The following example shows how to code a specific view for managed-SAM data sets:



      Notes about this view:

            1)   This example illustrates how to code a view to grant access to a single, or a collection of identical, SAM data set(s),
                  in VSAM space. Notice that virtually all data set attributes are defined. This eliminates the need to issue SITE
                  commands.

            2)   Also, notice that the file name has a Name of Day variable, &NDL3. Therefore, if you are writing (PUTing),
                  or reading (GETing), on a MONday, the server writes, or reads, FILE.MON.SAM. In other words, you can
                  use variables to have a specific view describe multiple, though identical, SAM data sets.

2. DISK-SAM (Sequential Data Set on DASD) Specific View :

       To correctly code a specific view for a sequential file on a DASD volume, you must code all
        relevent data set attributes required by the FTP server in order to read and write the data set.
        For more information about required data set attributes, please click here.

        The following example shows how to code a specific view for a DISK SAM data set:

3. TAPE-SAM (SAM on Tape) Specific Views:

       To correctly code a specific view for a sequential file on a TAPE volume, you must code all
        relevent data set attributes required by the FTP server in order to read and write the data set.
        For more information about required data set attributes, please click here.

        The following example shows how to code a specific view for a Tape data set:

XFER   = BEGIN
      TYPE                   = RCV
      TGT_FILE           = FILE.&NDL3.SAM   * <- - Specific view.. Never put a side comment where a file name is expected..

      TGT_AM             = SAM                         * Access method: SAM... Code as shown.
      TGT_TYPE          = VSAM                      * TYPE OF FILE is SAM in VSAM Space. Code as shown.
      TGT_DISP           = Mod
      TGT_RECF          = FB
      TGT_RECL          = 80
      TGT_BLOCKSZ   = 8000
      TGT_CATALOG = catalog_DLBL
      TGT_VOLSER     = tst000                     * stick the data set on this volume.
      TGT_SPACE_PRIM = 100
      TGT_SPACE_SEC   = 25


XFER         = END

XFER = begin
     TYPE       = RCV
     TGT_FILE   = TEST.SAM.FILE1
     TGT_AM     = SAM
     TGT_TYPE   = DISK
     TGT_FM       = NO                         Unmanaged DASD... No DASD SPACE MANAGER!!
     TGT_RECFM = FB                         Record Format
     TGT_RECL   = 121                         Logical Record Length
     TGT_BLKSZ = 12100                      Block size.
     TGT_DISP   = SHR                          Disposition.
     TGT_BUCKET = TST000:13365-98   Volume and extents..

XFER = END

XFER = begin
     TYPE       = RCV
     TGT_FILE   = TEST.FILE1
     TGT_AM     = SAM
     TGT_TYPE   = TAPE
     TGT_FM       = NO                         Unmanaged DASD... No DASD SPACE MANAGER!!
     TGT_RECFM = FB                         Record Format
     TGT_RECL   = 121                         Logical Record Length
     TGT_BLKSZ = 12100                      Block size.
     TGT_DISP   = NEW                        Disposition.
     TGT_UNIT =   790                         Tape is always preloaded onto tape drive 790
     TGT_VOLSER = 123456
     TGT_LABEL   = Standard

XFER = END