Change Debug (CHGDBG)

The Change Debug (CHGDBG) command changes the attributes of the debugging session currently in effect for a job. All of the attributes can be changed, except which programs to debug. Use the Add Program (ADDPGM) command or the Remove Program (RMVPGM) commands to add or remove a program from debug mode.

Restrictions:

This command is valid only in debug mode. To start debug mode, see the STRDBG (Start Debug) command.
If the current job is servicing another job, and that job is ending, this command is not allowed.

Parameters

Keyword	Description	Choices	Notes
DFTPGM	Default program	Name, SAME, NONE	Optional, Positional 1
MAXTRC	Maximum trace statements	Integer, *SAME	Optional
TRCFULL	Trace full	SAME, STOPTRC, *WRAP	Optional
UPDPROD	Update production files	SAME, NO, *YES	Optional
OPMSRC	OPM source level debug	SAME, NO, *YES	Optional

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Default program (DFTPGM)

Specifies the original program model (OPM) program to use as the default program during debug mode. The program specified here is used as the default program for any of the other debug commands for which *DFTPGM was supplied for the Program (PGM) parameter. (That is, if a default program was previously specified, this parameter can change it.)

This parameter is applicable only in the OPM environment.

*SAME: The same program currently specified as the default program, if any, is used.
*NONE: No program is specified as the default program; if a program was specified as a default program, it is no longer the default program. If the job has no default program, *DFTPGM cannot be specified for the Program (PGM) parameter of any other debug commands.
name: Specify the name of the program to use as the default program during debug mode. The same name must have been specified for the PGM parameter of the Start Debug (STRDBG) or Add Program (ADDPGM) command.

Maximum trace statements (MAXTRC)

Specifies the maximum number of trace statements that the system puts into the job's trace file before either stopping tracing or wrapping around (overlaying) on the trace file. When the trace file contains the maximum specified, the system performs the actions indicated by the value supplied for the Trace full (TRCFULL) parameter.

Note: Instruction stepping can be performed on a program being debugged in an interactive environment by setting the maximum number of trace statements to 1 and the value for the Trace full (TRCFULL) parameter to *STOPTRC.

This parameter is applicable only in the OPM environment.

*SAME: The maximum for the number of trace statements in the file is not changed.
integer: Specify the maximum number of trace statements that can be in the trace file.

Trace full (TRCFULL)

Specifies what happens when the job's trace file is full, that is when it contains the maximum number of trace statements specified by the Maximum trace statements (MAXTRC) parameter.

This parameter is applicable only in the OPM environment.

*SAME: The action taken when the trace file is full is not changed.
*STOPTRC: In a batch environment, tracing stops but the program continues processing. In an interactive environment, control is given to the user when a breakpoint occurs. If the user continues processing, a breakpoint occurs before processing each subsequent statement within the range of statements being traced, and the trace file is extended to contain the new entry.
*WRAP: The trace file is overlaid with new trace statements as they occur, wrapping from the beginning of the file. The program continues processing until completed with no message to indicate that wrapping has occurred. The trace file never has more than the maximum specified statements, and they are the most recently recorded statements.

Update production files (UPDPROD)

Specifies whether or not database files in a production library can be opened for changes (that is, for adding, deleting, or changing records in the file) while the job is in debug mode. If not, the files must be copied into a test library before trying to run a program that uses the files.

This parameter is applicable in both the OPM and ILE environments.

*SAME: The previously specified value for this parameter is not changed.
*NO: Database files in production libraries cannot be changed during debug mode. Database files can be opened for reading only.
*YES: Database files in production libraries can be changed while the job is in debug mode.

OPM source level debug (OPMSRC)

Specifies whether OPM programs are debugged using the system source debug support (same as ILE source debug).

This parameter is valid for OPM CL, OPM RPG and OPM COBOL programs that were created with OPTION(*SRCDBG) with CRTCLPGM, CRTRPGPGM and CRTCBLPGM commands. Additionally, this parameter is valid for OPM CL, OPM RPG and OPM COBOL programs that were created with OPTION(*LSTDBG) with the CRTCLPGM, CRTRPGPGM, CRTCBLPGM CRTSQLRPG, CRTSQLCBL, and CRTRPTPGM commands. If the OPM program is not CL, RPG or COBOL and was not compiled with a valid debug option, then this parameter is ignored.

OPM programs already added to debug prior to the CHGDBG command will continue to be active under the debug environment (ILE or OPM) they are currently active under. Programs added to debug after the CHGDBG command is issued are affected by the OPMSRC parameter.

This parameter is applicable in both OPM and ILE environment.

*SAME: The value does not change.

*NO: OPM debug functions are used for OPM programs.
*YES: ILE debug functions are used for OPM programs.

Examples

CHGDBG   MAXTRC(400)  TRCFULL(*STOPTRC)

This command changes the maximum number of trace statements that can be put in the trace file to 400. The tracing is stopped when the file is full.