Altering Load Modules

Altering Load Modules

Summary
  • IEBCOPY updates the load modules written by the link editor (before MVS/370) to load faster.
  • ALTERMOD statement is a one-time update operation used on load modules from old systems to make them compatible with the latest systems.
  • ALTERMOD performs the update operation on the load modules without taking a backup.

The ALTERMOD statement is ignored under these conditions -

  • The load modules are link edited with the noneditable (NE) attribute.
  • The dataset is a PDSE.
Note! The SELECT statement is used to identify the members and can't rename those members once processed.

Practical Example -

Scenario - Alter FIRSTPRG load in MATEPK.IEBCOPY.INPLOAD.

JCL -

----+----1----+----2----+----3----+----4----+----5----+----6----+----7--
//MATEPKI  JOB (123),'MTH',CLASS=A,MSGCLASS=A,MSGLEVEL=(1,1),           
//             NOTIFY=&SYSUID                                           
//***************************************************                   
//* ALTER FIRSTPRG LOAD MODULE FROM INPUT PDS                            
//***************************************************                   
//STEP10   EXEC PGM=IEBCOPY                                             
//SYSPRINT DD SYSOUT=*                                                  
//SYSOUT   DD SYSOUT=*                                                  
//SYSDUMP  DD SYSOUT=*                                                  
//SYSUT1   DD DSN=MATEPK.IEBCOPY.INPLOAD,DISP=(OLD,KEEP)                
//SYSUT2   DD UNIT=SYSDA,SPACE=(TRK,(5,1))                              
//SYSIN    DD *                                                         
 ALTERMOD  OUTDD=SYSUT1                                                 
       SELECT    MEMBER=(FIRSTPRG)                                      
/*

Output -

ALTERMOD Output

Explaining Example -

  • SYSUT1 DD DSN=MATEPK.IEBCOPY.INPLOAD - Specifies the PDS that has old load modules.
  • SYSUT2 DD - Provides the buffer space to process the operation.
  • SYSIN DD - Has the control statements for processing the input.
  • ALTERMOD OUTDD=SYSUT1 - Used to alter the load module from SYSUT1 DSN.
  • SELECT MEMBER=(FIRSTPRG) - FIRSTPRG member is the selected module for this operation.