Compaq AAQ2G1FTK -o, -g3, run, (ladebug), ladebug

Programming Productivity Tools
C.3 Ladebug Debugger (Tru64 UNIX)
this section is available in the man page. For example, you can type man cobol ,
and page to the appropriate topic to read information about the flags ( -g , -o ) used
at the beginning of the example in this section.
1. To begin this example you compile a CompaqCOBOL program consisting of
the single compilation unit named TESTA.
% cobol -g -o testa testa.cob
cobol: Warning: file not optimized; use -g3 for debug with optimize
%
The -g switch on the compiler command causes the compiler to write the
debugger symbol table associated with the program into the executable
program.
Normally,the compiler turns off optimization when you specify -g and gives a
warning to that effect. To debug your program with full optimization turned
on, use the -g3 switch.
2. The ladebug command starts the session. You provide your program name as
a parameter (argument) to the command. After the debugger reads in your
program’s symbol table, it returns control with its prompt,
(ladebug) .
% ladebug testa
Welcome to the Ladebug Debugger Version 2.0.8 eft
------------------
object file name: testa
Reading symbolic information ...done
(ladebug)
3. Set a breakpoint. In this case, you wish to break at line 43 of your program.
(ladebug) stop at 43
[#2: stop at "testa.cob":43 ]
4. Begin execution with the run command. The debugger starts program
TESTA, prompts for a keyboard entry,and waits for a response.
(ladebug) run
ENTER WORD
5. Enter the word to be reversed. Execution continues until the image reaches
the breakpoint at line 43 of the contained program.
abc
[2] stopped at [TESTB:43 0x120001aa4]
43 PERFORM LOOK-BACK VARYING SUB-1 FROM 20 BY -1
6. Set two breakpoints. You can give the debugger a list of commands to execute
at breakpoints; the commands are entered in braces ({} ).
(ladebug) stop at 47
[#2: stop at "testa.cob":47 ]
(ladebug) when at 50 { print chars of hold-chars; print SUB-1; cont; }
[#3: when at "testa.cob":50 { print CHARS of HOLD-CHARS; print SUB-1; ; cont ; } ]
7. Display the active breakpoints.
(ladebug) status
#1 PC==0x120001e14 in testa "testa.cob":2 { break }
#2 PC==0x120001ba4 in TESTB "testa.cob":47 { break }
#3 PC==0x120001c1c in TESTB "testa.cob":50
{ ; print CHARS of HOLD-CHARS; print SUB-1; ; cont ; ; }
Programming Productivity Tools C–5