IEBCOPY Altering Load Modules

Summary -

In this topic, we described about the Altering Load Modules with detailed example.

ALTERMOD is designed as a one-time update operation against load modules from old systems. IEBCOPY to update PDS load modules written prior to MVS/370, so that they will load faster.

ALTERMOD will place correct relocation dictionary counts and segment block counts into control records inside the module.

ALTERMOD performs the above update without making a new copy of the load module. The ALTERMOD statement ignored under these conditions:

The load modules are link edited with the noneditable (NE) attribute.
The data set is a PDSE.

Note! When SELECT statement used to identify members to be processed by ALTERMOD can’t be renamed.

Example:

All members of data set dataset1.lib, members A, B, and C of data set are altered in place.

//ALTERONE JOB  ...
  //STEPA    EXEC PGM=IEBCOPY
  //SYSPRINT DD  SYSOUT=A
  //SYSUT3   DD  UNIT=SYSDA,SPACE=(TRK,(5,1))
  //Dataset1DD  DSNAME=dataset1.lib,DISP=(OLD,KEEP)
  //SYSIN    DD  *
	ALTERMOD  OUTDD=Dataset1
       SELECT    MEMBER=(A,B)
  /*

Let’s discuss the example in detail.

Dataset1 DD defines the partitioned data set dataset1.lib, which has been previously created and cataloged.
SYSIN DD defines the control data set, which follows in the input stream.
The ALTERMOD statement plus the following SELECT statement indicates that members A and B are to be altered in place.
The remainder of dataset1.lib is unchanged.