Binder Language Example 3

As the application continues to grow, two new procedures are needed to complete our financial package. The two new procedures, OpenAccount and CloseAccount, open and close the accounts, respectively. The following steps need to be performed to update MYLIB/FINANCIAL such that the program BANKER does not need to be re-created:

1. Write the procedures OpenAccount and CloseAccount.
2. Update the binder language to specify the new procedures.

The updated binder language supports the new procedures. It also allows the existing ILE programs or service programs that use the FINANCIAL service program to remain unchanged. The binder language looks like this:

FILE: MYLIB/QSRVSRC  MEMBER: FINANCIAL
 
STRPGMEXP  PGMLVL(*CURRENT)
  EXPORT SYMBOL('Term')
  EXPORT SYMBOL('Rate')
  EXPORT SYMBOL('Amount')
  EXPORT SYMBOL('Payment')
  EXPORT SYMBOL('OpenAccount')
  EXPORT SYMBOL('CloseAccount')
ENDPGMEXP
 
STRPGMEXP  PGMLVL(*PRV)
  EXPORT SYMBOL('Term')
  EXPORT SYMBOL('Rate')
  EXPORT SYMBOL('Amount')
  EXPORT SYMBOL('Payment')
ENDPGMEXP

When an update operation to a service program is needed to do both of the following:

• Support new procedures or data items
• Allow the existing programs and service programs that use the changed service program to remain unchanged

one of two alternatives must be chosen. The first alternative is to perform the following steps:

1. Duplicate the STRPGMEXP, ENDPGMEXP block that contains PGMLVL(*CURRENT).
2. Change the duplicated PGMLVL(*CURRENT) value to PGMLVL(*PRV).
3. In the STRPGMEXP command that contains PGMLVL(*CURRENT), add to the end of the list the new procedures or data items to be exported.
4. Save the changes to the source file.
5. Create or re-create the new or changed modules.
6. Create the service program from the new or changed modules by using the updated binder language.

The second alternative is to take advantage of the signature parameter on the STRPGMEXP command and to add new symbols at the end of the export block:

STRPGMEXP PGMVAL(*CURRENT) SIGNATURE('123')
  EXPORT SYMBOL('Term')
    .
    .
    .
   EXPORT SYMBOL('OpenAccount')
   EXPORT SYMBOL('CloseAccount')
ENDPGMEXP

To create the enhanced service program shown in Figure 1, the updated binder language shown in Binder Language Example 3 is used on the following CRTSRVPGM command:

 CRTSRVPGM  SRVPGM(MYLIB/FINANCIAL)
            MODULE(MYLIB/MONEY MYLIB/RATES MYLIB/CALCS MYLIB/ACCOUNTS))
            EXPORT(*SRCFILE)
            SRCFILE(MYLIB/QSRVSRC)
            SRCMBR(*SRVPGM)