Compaq COBOL AAQ2G1FTK - Manual (Page 575)

Programming Productivity Tools
C.4 OpenVMS Debugger (OpenVMS)
11. Set a watchpoint on the data item DISP-COUNT. When an instruction tries
to change the contents of DISP-COUNT, the debugger returns control to you.
DBG> SET WATCH DISP-COUNT
DEBUG-I-WPTTRACE, non-static watchpoint, tracing every instruction
12. Execution resumes with the GO command. Before line 50 in TESTB executes,
the debugger executes the contents of the DO command entered at step 7. It
displays the contents of HOLD-CHARS and SUB-1, then resumes execution.
DBG> GO
break at TESTA\TESTB\%LINE 50
50: SUBTRACT 1 FROM SUB-1.
TESTA\TESTB\HOLD-CHARS:
CHARS: "c "
TESTA\TESTB\SUB-1: 3
break at TESTA\TESTB\%LINE 50
50: SUBTRACT 1 FROM SUB-1.
TESTA\TESTB\HOLD-CHARS
CHARS: "cb "
TESTA\TESTB\SUB-1: 2
break at TESTA\TESTB\%LINE 50
50: SUBTRACT 1 FROM SUB-1.
TESTA\TESTB\HOLD-CHARS
CHARS: "cba "
TESTA\TESTB\SUB-1: 1
break at TESTA\TESTB\%LINE 47
47: MOVE HOLD-WORD TO TEMP-WORD.
DBG>
13. Examine the contents of SUB-1.
DBG> EXAMINE SUB-1
TESTA\TESTB\SUB-1:
0
14. Deposit the value –42 into data item SUB-2.
DBG> DEPOSIT SUB-2 = -42
15. Examine the contents of SUB-2.
DBG> EXAMINE SUB-2
TESTA\TESTB\SUB-2:
-42
16. Examine the contents of CHARCT, whose picture is 99V99.
DBG> EXAMINE CHARCT
TESTA\TESTB\CHARCT:
3.00
17. Deposit four characters into CHARCT.
DBG> DEPOSIT CHARCT=15.95
18. CHARCT now contains 15.95.
DBG> EXAMINE CHARCT
TESTA\TESTB\CHARCT:
15.95
19. Deposit an integer larger than CHARCT’s definition. The debugger returns
an error message.
DBG> DEPOSIT CHARCT=2890
%DEBUG-E-DECOVF, decimal overflow at or near DEPOSIT
20. Examine the contents of CHARCT.
DBG> EXAMINE CHARCT
TESTA\TESTB\CHARCT:
15.95
Programming Productivity Tools C–11