bdfu1m1dUtilities

ZUDFM OAF-Display Forward and Backward Chaining

Use this command to display the forward and backward chaining information of a subfile or an 8-character (4-byte) hexadecimal file address.

Requirements and Restrictions

Output from the ZUDFM OAF command stops after 500 chains have been displayed.

Format




Note:
You can use either the ZUDFM OAF or the ZUDFM FCH command.

fileaddr
specifies an 8-character hexadecimal file address.

Additional Information

Examples

This following example displays the forward chaining, backward chaining, or both, of the currently linked file.

+--------------------------------------------------------------------------------+
|User:   ZUDFM OAF                                                               |
|                                                                                |
|System: UDFM0221I          OAF  F.A. F402D808  ID FDEC  RCC 00                  |
|                                                                                |
|        NBR  FILEADDR PGM  FWDCHAIN BCKCHAIN BLOCK TRAILER     COMMAND          |
|        ---------------------------------------------------------------         |
|        000  F402D808 QT19 000C05A9 000C05A5 25JUN97 11.40.42  CLOSE            |
|        001  000C05A9 QT19 000C05A5          25JUN97 11.39.52  ADD              |
|        002  000C05A5 QT19 00000000          25JUN97 11.40.42  CLOSE            |
+--------------------------------------------------------------------------------+

The following describes the information provided in the previous example:

 FA 
The file address of the block.

 ID 
The file ID of the block.

 RCC 
A 1-byte field that contains the record code check (RCC). This is a 1-byte value that is common to all the blocks that are being pointed to in the subfile.

 NBR 
The relative number of the block in the chain.

 FILEADDR 
The file address of the block.

 PGM 
The program stamp of the block, which is held in the STDPGM field.

 FWDCHAIN 
The file address of the block to which this block is forward chained.

 BCKCHAIN 
The file address of the block to which this block is backward chained. (The BCKCHAIN field in the prime block points to the address of the last block in the chain.)
Note:
The backward chain is not displayed if it is zero. This indicates that the file does not use full backward chaining.

 BLOCK TRAILER 
The date and time in which the block was written to DASD.

 COMMAND 
Indicates the TPFDF macro for the function that was used to write the block. In this example, CLOSE indicates the DBCLS macro or dfcls functions.

The following example displays the forward chaining, backward chaining, or both, of a specific file address.

+--------------------------------------------------------------------------------+
|User:   ZUDFM OAF/000C05A9                                                      |
|                                                                                |
|System: UDFM0221I          OAF  F.A. 000C05A9  ID FDEC  RCC 00                  |
|                                                                                |
|        NBR  FILEADDR PGM  FWDCHAIN BCKCHAIN BLOCK TRAILER     COMMAND          |
|        ---------------------------------------------------------------         |
|        000  000C05A9 QT19 000C05A5          25JUN97 11.39.52  ADD              |
|        001  000C05A5 QT19 00000000          25JUN97 11.40.42  CLOSE            |
+--------------------------------------------------------------------------------+

References

See the following for more information about linking to a subfile: