Modifying the value of a COBOL variable

To list the contents of a single variable, move the cursor to an occurrence of the variable name in the Source window and press PF4 (LIST). Remember that z/OS® Debugger starts after program initialization but before symbolic COBOL variables are initialized, so you cannot view or modify the contents of variables until you have performed a step or run. The value is displayed in the Log window. This is equivalent to entering LIST TITLED variable on the command line. Run the COBCALC program to the statement labeled  CALC1 , and enter AT 46 ; GO ; on the z/OS Debugger command line. Move the cursor over INPUT-1 and press LIST (PF4). The following appears in the Log window:

 LIST ( INPUT-1 ) ;
INPUT-1 = 'LOAN      '

To modify the value of INPUT-1, enter on the command line:

MOVE 'pvalue' to INPUT-1 ;

You can enter most COBOL expressions on the command line.

Now step into the call to COBVALU by pressing PF2 (STEP) and step until the statement labeled  VALU2  is reached. To view the attributes of the variable INTEREST, issue the z/OS Debugger command:

DESCRIBE ATTRIBUTES INTEREST ;

The result in the Log window is:

ATTRIBUTES FOR INTEREST
  ITS LENGTH IS 4
  ITS ADDRESS IS 00011DC8
  02 COBVALU:>INTEREST   S999V99 COMP

You can use this action as a simple browser for group items and data hierarchies. For example, you can list all the values of the elementary items for the CHAR-DATA group with the command:

LIST CHAR-DATA ;

with results in the Log window appearing something like this:

 LIST CHAR-DATA ;
02 COBVALU:>INPUT-1  of 01 COBVALU:>CHAR-DATA  = '.12 5     '
Invalid data for 02 COBVALU:>PAYMENT-OUT  of 01 COBVALU:>CHAR-DATA   is found.
02 COBVALU:>INTEREST-IN  of 01 COBVALU:>CHAR-DATA  = '.12  '
02 COBVALU:>NO-OF-PERIODS-IN  of 01 COBVALU:>CHAR-DATA  = '5  '
02 COBVALU:>INPUT-BUFFER  of 01 COBVALU:>CHAR-DATA  = '5069837544'
SUB(1) of 02 COBVALU:>BUFFER-ARRAY  of 01 COBVALU:>CHAR-DATA  = '50'
SUB(2) of 02 COBVALU:>BUFFER-ARRAY  of 01 COBVALU:>CHAR-DATA  = '69'
SUB(3) of 02 COBVALU:>BUFFER-ARRAY  of 01 COBVALU:>CHAR-DATA  = '83'
SUB(4) of 02 COBVALU:>BUFFER-ARRAY  of 01 COBVALU:>CHAR-DATA  = '75'
SUB(5) of 02 COBVALU:>BUFFER-ARRAY  of 01 COBVALU:>CHAR-DATA  = '44'