Using the interactive debugger - Revision history

PoC: /* Weblinks / DS4 mode

2025-09-06T16:30:45Z

Weblinks: *DS4 mode

← Older revision		Revision as of 18:30, 6 September 2025
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	** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs ''Debugging Programs'' for RPG]		** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs ''Debugging Programs'' for RPG]
	* [https://archive.midrange.com/c400-l/202509/msg00002.html Debugging C program strings with STRDBG], answer from Stephen West for dereferencing pointer variables		* [https://archive.midrange.com/c400-l/202509/msg00002.html Debugging C program strings with STRDBG], answer from Stephen West for dereferencing pointer variables
			* [http://www.ibm.com/support/pages/debugger-does-not-display-source-wide-screen-mode Debugger Does Not Display Source in Wide Screen Mode], ibm.com

	== Footnotes ==		== Footnotes ==

PoC: /* Special case: C */ decoding options

2025-09-05T11:33:41Z

Special case: C: decoding options

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	In C, strings are in reality arrays of chars. Without any further instructions, the debugger will show you the base address of that array. If you wish to see the array contents, you need to instruct the debugger to ''dereference'' the address, and pull the content up to 20 elements:		In C, strings are in reality arrays of chars. Without any further instructions, the debugger will show you the base address of that array. If you wish to see the array contents, you need to instruct the debugger to ''dereference'' the address, and pull the content up to 20 elements:
	EVAL *variable:c 20		EVAL *variable:c 20

			The appendix <code>:c</code> can be:
			* <code>:a</code> for ASCII character string,
			* <code>:c</code> for character string,
			* <code>:x</code> for decode to hex,

	More complex constructs can be dissected likewise.		More complex constructs can be dissected likewise.

PoC: /* Weblinks */ +link

2025-09-04T08:48:45Z

Weblinks: +link

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	** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program ''Debugging Programs'' for COBOL]		** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program ''Debugging Programs'' for COBOL]
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs ''Debugging Programs'' for RPG]		** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs ''Debugging Programs'' for RPG]
			* [https://archive.midrange.com/c400-l/202509/msg00002.html Debugging C program strings with STRDBG], answer from Stephen West for dereferencing pointer variables

	== Footnotes ==		== Footnotes ==

PoC: /* Running the program in debug mode */ Better structure

2025-09-04T08:47:24Z

Running the program in debug mode: Better structure

← Older revision		Revision as of 10:47, 4 September 2025
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	Especially outputting variable contents with <code>F11</code> is extremely helpful.		Especially outputting variable contents with <code>F11</code> is extremely helpful.

			=== Special case: C ===
	If you're debugging C programs, and look at a string variable with <code>F11</code>, you'll get output in the message line akin to the following:		If you're debugging C programs, and look at a string variable with <code>F11</code>, you'll get output in the message line akin to the following:
	variable = SPP:F441AE89590012B2		variable = SPP:F441AE89590012B2

PoC: /* Running the program in debug mode */ Hint from Stephen West

2025-09-04T08:46:16Z

Running the program in debug mode: Hint from Stephen West

@@ Line 28: / Line 28: @@
 * inspect variable contents by placing the cursor appropriately, and pressing <code>F11</code>,
 * set watches to variables by placing the cursor appropriately, and pressing <code>F17</code>.
 If you're done, press <code>F3</code> to end your program.

PoC: /* Weblinks */ Better links

2025-09-04T08:39:17Z

Weblinks: Better links

← Older revision		Revision as of 10:39, 4 September 2025
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	* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command \| How to Debug RPGLE Program \| RPGLE Free Form in AS400 (IBM i) \| VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>		* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command \| How to Debug RPGLE Program \| RPGLE Free Form in AS400 (IBM i) \| VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>
	* Related documentation for debugging ILE languages on ''ibm.com'':		* Related documentation for debugging ILE languages on ''ibm.com'':
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=guide-debugging-programs for C/C++]		** [https://www.ibm.com/docs/en/i/7.6.0?topic=guide-debugging-programs ''Debugging Programs'' for C/C++]
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program for COBOL]		** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program ''Debugging Programs'' for COBOL]
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs for RPG]		** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs ''Debugging Programs'' for RPG]

	== Footnotes ==		== Footnotes ==

PoC: /* Weblinks */ Typo

2025-09-04T08:38:47Z

Weblinks: Typo

← Older revision		Revision as of 10:38, 4 September 2025
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	== Weblinks ==		== Weblinks ==
	* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command \| How to Debug RPGLE Program \| RPGLE Free Form in AS400 (IBM i) \| VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>		* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command \| How to Debug RPGLE Program \| RPGLE Free Form in AS400 (IBM i) \| VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>
	* Related documentation for ILE languages on ''ibm.com'':		* Related documentation for debugging ILE languages on ''ibm.com'':
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=guide-debugging-programs] for C/C++		** [https://www.ibm.com/docs/en/i/7.6.0?topic=guide-debugging-programs for C/C++]
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program] for COBOL		** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program for COBOL]
	** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs] for RPG		** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs for RPG]

	== Footnotes ==		== Footnotes ==

PoC: /* Weblinks */ +links

2025-09-04T08:38:26Z

Weblinks: +links

← Older revision		Revision as of 10:38, 4 September 2025
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	== Weblinks ==		== Weblinks ==
	* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command \| How to Debug RPGLE Program \| RPGLE Free Form in AS400 (IBM i) \| VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>		* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command \| How to Debug RPGLE Program \| RPGLE Free Form in AS400 (IBM i) \| VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>
			* Related documentation for ILE languages on ''ibm.com'':
			** [https://www.ibm.com/docs/en/i/7.6.0?topic=guide-debugging-programs] for C/C++
			** [https://www.ibm.com/docs/en/i/7.6.0?topic=programs-debugging-program] for COBOL
			** [https://www.ibm.com/docs/en/i/7.6.0?topic=handling-debugging-programs] for RPG

	== Footnotes ==		== Footnotes ==

PoC: Better wording

2025-08-31T21:03:33Z

Better wording

← Older revision		Revision as of 23:03, 31 August 2025
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	With no prior experience, '''using the interactive debugger''' can be quite frustrating. This article should provide a quick start to the uninitiated.		With no prior experience, getting into '''using the interactive debugger''' can be quite frustrating. This article should provide a quick start to the uninitiated.

	== Compile program with debugging information ==		== Compile program with debugging information ==

PoC: New

2025-08-31T12:10:55Z

New

New page

With no prior experience, '''using the interactive debugger''' can be quite frustrating. This article should provide a quick start to the uninitiated.

== Compile program with debugging information ==
The debugger is more helpful, the more source information is imbedded into the final program object. For an ILE RPG application, simply
* call up <code>wrkmbrpdm</code> with the source file containing the member of the program to be debugged,
* type 14 into the line with the application you wish to debug — and do '''not''' press enter yet,
* add <tt>dbgview(*all)</tt> into the command line at the screen bottom,
* and finally press enter to compile the source to the eventual ''*pgm'' object.

== Switching on debug mode ==
This is done by issuing the command
strdebug<ref>This is a restricted command. It can be used only by user profiles
* being member of the ''qpgmr'' group profile,
* having ''*allobj'' authority.
</ref>
with appropriate options. Prompt with <code>F4</code>.
* The ''pgm'' option is very helpful to limit the debugging scope to the desired application(s).
* The <code>updprod(*yes)</code> is necessary if your program relies on using files from a normal<ref>The <code>crtlib</code> command has a parameter <code>type(*prod|*test)</code></ref> ''*prod'' type library.

After pressing enter, you'll be presented with the ''Display Module Source'' screen. From here you can scroll through the imbedded code to set or delete so called breakpoints. These are tags in code lines, where the normal program handling is suspended, and the debugger screen (Display Module Source) is called up again.

== Running the program in debug mode ==
If you've set one or more appropriate breakpoints, exit the ''Display Module Source'' screen with <code>F3</code>, and run your program object as intended. Most often you'll <code>call</code> it from the command line:
call mypgm

The program will now run as usual until the first breakpoint is hit. Then, the ''Display Module Source'' screen is displayed again, showing the current line the program's execution was suspended due to the breakpoint. From here, you can
* single-step through the program with <code>F10</code>,
* inspect variable contents by placing the cursor appropriately, and pressing <code>F11</code>,
* set watches to variables by placing the cursor appropriately, and pressing <code>F17</code>.

If you're done, press <code>F3</code> to end your program.

== Ending debug mode ==
Issue the following command:
enddbg

== Weblinks ==
* [https://www.youtube.com/watch?v=suwow1bGh1o STRDBG Command | How to Debug RPGLE Program | RPGLE Free Form in AS400 (IBM i) | VCP Technology ], Video on YouTube (9:29)<ref>The presenter has a very strong accent, possibly making it very hard to understand what he's saying.</ref>

== Footnotes ==
<references />

[[Category: Programming]]