Use this command to display blocked tapes online. You
can:
- Display records on a blocked tape
- Shift a blocked tape forward or backward
- Search a blocked tape for a specific item.
A blocked tape is a tape of physical records that can consist of
one or more contiguous logical records or parts of logical records.
Physically, the blocked tape is read one record at a time; logically, the
TPF system manages the blocked tape record by record.
Requirements and Restrictions
- The specified blocked tape must be mounted as a DBL active input tape
using the ZTMNT command. A DBL tape label must exist before entering
the ZDEBB command.
- The ZDEBB command can be used only to process a single tape. If
ZDEBB command processing encounters a tape mark with an end-of-volume (EOV)
label on the DBL tape, the TPF system treats the EOV condition as an
end-of-file (EOF) condition and does not attempt to switch to a standby DBL
tape. To process multiple blocked tapes in a dataset, use the ZDEBB
command separately for each tape.
- The display and print tape block parameters (FD, FP, RD, RP, SD, SP, TD,
and TP) require that the TPF system is in a state where the get file storage
(GFS) facility is active (that is, computer room agent set (CRAS) state or
higher). In addition, the TPF system must not be cycling to 1052
state. For the SD and SP parameters, the tape search takes place before
checking these constraints and displaying the tape information.
- After displaying logical records on the blocked tape or searching for
information in a logical record, enter the ZDEBB command with the RU parameter
specified to do the following:
- Rewind and unload the blocked tape
- Remove the DBL entry from the tape status table.
Format
- RU
- rewinds and unloads the blocked tape. If this is not done, the DBL
tape will remain mounted.
- RW
- rewinds the blocked tape.
- SF
- shifts the blocked tape forward one or more logical records.
- TD
- performs a tape block hexadecimal dump of the next logical record.
- TP
- prints the next logical record in character format.
- BB
- shifts the blocked tape backward the specified number of physical
blocks.
- blocks
- is the number of physical blocks from 0000-9999.
- FD
- shifts the blocked tape forward the specified number of logical records
and performs a tape block hexadecimal dump (SR and TD).
- FP
- shifts the blocked tape forward the specified number of logical records
and prints the tape block in character format (SR and TP).
- RD
- shifts the blocked tape backward the specified number of logical records
and performs a tape block hexadecimal dump (BB and TD).
- RP
- shifts the blocked tape backward the specified number of logical records
and prints the tape block in character format (BB and TP).
- SR
- shifts the blocked tape forward the specified number of logical
records.
- records
- is the number of logical records from 0000-9999.
- SD
- searches the blocked tape for the specified data and performs a tape block
hexadecimal dump (TS and TD).
- SP
- searches the blocked tape for the specified data and prints the tape block
in character format (TS and TP).
- TS
- searches the blocked tape for the specified data.
- displacement
- is the 3-byte hexadecimal displacement in the logical record.
- C
- indicates that the data is character data.
- X
- indicates that the data is hexadecimal data.
- -data-
- is the character or hexadecimal data.
- Note:
- You must begin and end the data with the - character.
Additional Information
None.
Examples
The blocked tape is rewound in the following example.
+--------------------------------------------------------------------------------+
|User: ZDEBB RW |
| |
|System: CSAV0000I 11.44.53 OPERATION COMPLETE |
+--------------------------------------------------------------------------------+
The next tape block is displayed in the following example.
+--------------------------------------------------------------------------------+
|User: ZDEBB TP |
| |
|System: CSAW0000I 11.44.53 TAPE DATA RECORD DISPLAY |
| 000 T D 1 0 5 5 B L K 0 0 0 0 0 1 |
| 010 9 9 900 00000000 00000000 00000000 |
| 410 5C E N D O F R E C O R D5C O |
| END OF DISPLAY - RECORD LENGTH IS 1055 |
+--------------------------------------------------------------------------------+
The blocked tape is shifted forward 1 block in the following
example.
+--------------------------------------------------------------------------------+
|User: ZDEBB SR 0001 |
| |
|System: CSAV0000I 14.45.34 OPERATION COMPLETE |
+--------------------------------------------------------------------------------+
The blocked tape is shifted backward one physical block and the logical
record is printed in character format in the following example.
+--------------------------------------------------------------------------------+
|User: ZDEBB RP 0001 |
| |
|System: CSAW0000I 11.44.53 TAPE DATA RECORD DISPLAY |
| 000 T D 1 0 5 5 B L K 0 0 0 0 0 2 |
| 010 0 0 000 00000000 00000000 00000000 |
| 410 5C E N D O F R E C O R D5C O |
| END OF DISPLAY - RECORD LENGTH IS 1055 |
+--------------------------------------------------------------------------------+
Related Information
None.