SHOWCB—Display fields of an exit list

The format of the SHOWCB macro used to display fields in an exit list is:

[label]

SHOWCB

EXLST=address
,AREA=address
,LENGTH=abs expression
,FIELDS=([EODAD] [,EXLLEN] [,JRNAD]
[,LERAD][,SYNAD])

The subparameters of the SHOWCB macro can be expressed as absolute numeric expressions, as character strings, as codes, as expressions that generate valid relocatable A-type address constants, in register notation, as S-type address constants, and as indirect S-type address constants. Subparameters with GENCB, MODCB, SHOWCB, and TESTCB, further defines these operand expressions.

label

specifies 1 to 8 characters that provide a symbolic address for the SHOWCB macro.

EXLST=address

specifies the address of the exit list whose fields are displayed. If you used the EXLST macro with a label, you can specify the label here. The EXLST parameter is optional only when you want to display the length an exit list can have (see FIELDS=EXLLEN below). The SHOWCB macro does not support the UPAD user exit.

AREA=address

specifies the address of a return area you supply for VSAM to display the contents of the fields specified in the FIELDS parameter. The contents of the fields are displayed in the order specified. The area must begin on a fullword boundary.

LENGTH=abs expression

specifies the length, in bytes, of the return area you provide for VSAM to display the indicated fields in. Each exit-list field requires a fullword. If the area is not large enough for all the fields, VSAM does not display any of their contents and returns an error code (see Control block manipulation macro return and reason codes).

FIELDS=([EODAD][,EXLLEN][,JRNAD]

[,LERAD][,SYNAD])

specifies the values to display, as follows:

EODAD: specifies the address of the end-of-data-set routine is displayed.
EXLLEN: specifies the length of the exit list indicated in the EXLST parameter or if EXLST is omitted, the maximum length an exit length can have, is displayed.
JRNAD: specifies the address of the journalizing routine is displayed.
LERAD: specifies the address of the logical error analysis routine is displayed.
SYNAD: specifies the address of the physical error analysis routine is displayed.

You can use SHOWCB to display the address of an exit routine only if the exit routine is indicated in the exit list. If it is not, the SHOWCB request fails. Use TESTCB to test whether an entry for a given exit type is present in the exit list and to find out whether the exit is active and the routine is to be loaded.