How to Use CULLUS22

Procedure Modules › Random Access of ISAM Files (CULLUS22) › How to Use CULLUS22

How to Use CULLUS22

Preparing to Use CULLUS22

Define the ISAM data set in the execution JCL:

System	Step	JCL statements *
z/OS	CULL	Define the ISAM file on the US22 DD statement: //US22 DD DSN=user.file,UNIT=disk, DISP=shr,VOL=SER=nnnnnn
z/VSE	CULL	// ASSGN SYS004,DISK,VOL=nnnnnn // DLBL filename,'file-id',ISE // EXTENT SYS004,nnnnnn,4,1,rt,nt // EXTENT SYS004,nnnnnn,1,2,rt,nt // EXTENT SYS004,nnnnnn,2,3,rt,nt rt = relative track where the data extent begins nt = number of tracks allocated to this file
z/VM		ISAM is not supported.

System

Step

JCL statements *

z/OS

CULL

Define the ISAM file on the US22 DD statement:

//US22 DD DSN=user.file,UNIT=disk,

DISP=shr,VOL=SER=nnnnnn

z/VSE

CULL

// ASSGN SYS004,DISK,VOL=nnnnnn

// DLBL filename,'file-id',ISE

// EXTENT SYS004,nnnnnn,4,1,rt,nt

// EXTENT SYS004,nnnnnn,1,2,rt,nt

// EXTENT SYS004,nnnnnn,2,3,rt,nt

rt = relative track where the

data extent begins

nt = number of tracks allocated

to this file

z/VM

ISAM is not supported.

Note: * See the CA Culprit for CA IDMS Reference Guide for a full explanation of the syntax.

If accessing more than one ISAM file:

First—Modify the CULLUS22 Assembler source code:

System	Modification
z/OS	Change the DDNAME keyword in the DCB macro
z/VSE	Use unique filenames in the DTF macro for each copy of CULLUS22
z/VM	ISAM is not supported.

Second—Reassemble and link edit each modification of CULLUS22 using unique names.

Using CULLUS22

To invoke CULLUS22:

First—Define a field that contains the key required to retrieve records from the ISAM file. The format of the key field depends on the operating system:

System...	The key format...
z/OS	The same as the ISAM key
z/VSE	8-byte packed decimal

Second—Define a dummy buffer area equal to the length of the retrieved record.

For non-database runs, use the MB= option on an additional INPUT parameter.
For database runs, use one INPUT parameter that includes the extra storage requirement in the record size specification.

Third—Define a 1-byte alphanumeric work field to act as a communications switch.

Fourth—Issue a CALL to CULLUS22 from type 7 logic:

Col
2
▼
RPT-nn7sss CALLL US22 (return-position-v field-v key-v)

Rpt-nn, coded in columns 2 and 3, specifies a 2-digit number in the range 00 through 99 that identifies the CA Culprit report.
Sss, coded in columns 5 through 7, specifies a 3-digit number indicating the sequence number of the type 7 parameter.
Return-position-v (ARG1) requires the name of an input or work field to which the retrieved ISAM record is moved.
Field-v (ARG2) requires the name of a 1-byte work field that acts as a communications switch for passing information between type 7 code and CULLUS22. The work field can contain the following values:

The value...	Set by...	Means...
Any but C*	User	OPEN file and READ.
C	User	CLOSE file.
Y	CULLUS22	Record found.
N	CULLUS22	Record not found.
E	CULLUS22	Error on READ.
Z (z/OS ONLY)	CULLUS22	OPEN file. Zero key length in the DCB. (probable JCL error)

Note: * CULLUS22 accepts any value other than C as a READ instruction.

Key-v (ARG3) requires the name of the ISAM key field used for retrieval. This argument can be set to an input or a work field. If set to a work field, the value will be stored in packed decimal format.

Fifth—Test the value of the communications switch (ARG2) in type 7 logic.