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.
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.