Methods available for specifying runtime options

Language Environment® runtime options can be specified in the following ways:

As system-level defaults
Runtime options can be established as system-level defaults through a member in the system parmlib. The format of the parmlib member name is CEEPRMxx. The member is identified during IPL by a CEE=xx statement, either in the IEASYSyy data set or in the IPL PARMS. After IPL, the active parmlib member can be changed with a SET CEE=xx command. Individual options can be changed with a SETCEE command.

For more information about specifying system-level default options, see z/OS MVS Initialization and Tuning Reference and Creating system-level option defaults with CEEPRMxx in z/OS Language Environment Customization.

As region-level defaults
The CEEXOPT macro can be used to create a CEEROPT load module to establish defaults for a particular region. CEEROPT is optional, but if it is used, code just the runtime options to be changed. Runtime options that are omitted from CEEROPT will remain the same as the system-level defaults (if present) or IBM®-supplied defaults. The CEEROPT module resides in a user-specified load library.

For more information about specifying region-level defaults, see Creating region-level runtime option defaults with CEEXOPT in z/OS Language Environment Customization.

In the CLER CICS® transaction
The CICS transaction CLER allows you to display all the current Language Environment runtime options for a region, and to also to modify a subset of these options.
The following runtime options can be modified with the CLER transaction:
  • ALL31(ON|OFF)
  • CBLPSHPOP(ON|OFF)
  • CHECK(ON|OFF)
  • HEAPZONES(0-1024,QUIET|MSG|TRACE|ABEND)
  • INFOMSGFILTER(ON|OFF)
  • RPTOPTS(ON|OFF)
  • RPTSTG(ON|OFF)
  • TERMTHDACT(QUIET|MSG|TRACE|DUMP|UAONLY|UATRACE| UADUMP|UAIMM)
  • TRAP(ON|OFF)

Setting RPTOPTS(ON) or RPTSTG(ON) in a production environment can significantly degrade performance. Also, if ALL31(OFF) is set in a production environment, the stack location will be set to BELOW the 16 MB line, which could cause the CICS region to abend due to lack of storage.

The LAST WHERE SET column of the Language Environment runtime options report contains CICS CLER Trans for those options that were set by CLER.

Note: CICS TS 3.1 and later supports XPLINK programs in a CICS environment. The CLER transaction does not affect the runtime options for these programs.
As application defaults
The CEEUOPT assembler language source program sets application defaults using the CEEXOPT macro. The CEEUOPT source program can be edited and assembled to create an object module, CEEUOPT. The CEEUOPT object module must be linked with an application to establish application defaults.
In the assembler user exit
See CEEBXITA assembler user exit interface for information about how to specify a list of runtime options in the assembler user exit.

For IMS, the UPDATE LE command can be used with the IMS-supplied CEEBXITA exit, DFSBXITA, to allow dynamic overrides for runtime options. For more information about the UPDATE LE command and the IMS-supplied CEEBXITA exit, DFSBXITA, see the IBM Knowledge Center at IMS in IBM Knowledge Center.

In the storage tuning user exit
The storage tuning user exit can be used to set the Language Environment storage options STACK, LIBSTACK, HEAP, ANYHEAP, and BELOWHEAP. For more information about the storage tuning user exit, see Storage tuning user exit in z/OS Language Environment Customization.
Note: Vendor Heap Manager activity is not handled by the Language Environment storage tuning user exit.
In TSO/E commands, on application invocation
You can specify runtime options as options on the CALL command. See Running your application under TSO/E for more information.
In the _CEE_RUNOPTS environment variable
If you run C applications that are invoked by one of the exec family of functions, you can use the environment variable _CEE_RUNOPTS to specify invocation Language Environment runtime options. For more information about _CEE_RUNOPTS, see _CEE_RUNOPTS in z/OS XL C/C++ Programming Guide in z/OS XL C/C++ Programming Guide.
As JCL

You can specify runtime options in the PARM parameter of the JCL EXEC statement or as a DD card named CEEOPTS. See Specifying runtime options in the EXEC statement and Specifying runtime options with the CEEOPTS DD card for details.

In your source code:
C and C++
C provides the #pragma runopts directive, with which you can specify runtime options in your source code.

You must specify #pragma runopts in the source file that contains your main function, before the first C statement. Only comments and other pragma can precede #pragma runopts.

Specify #pragma runopts as follows:

Read syntax diagramSkip visual syntax diagram #pragma runopts ( ,option )

where option is a Language Environment runtime option.

For more information about using C/C++ pragma, see #pragma runopts in z/OS XL C/C++ Language Reference.

PL/I
Runtime options can be specified in a PL/I source application with the following declaration: 
DCL PLIXOPT CHAR(length) VAR INIT('string')
            STATIC EXTERNAL;
where string is a list of options separated by commas or blanks, and length is a constant equal to or greater than the length of string. Runtime options in PLIXOPT are parsed by the compiler. For Enterprise PL/I for z/OS and PL/I for MVS & VM, the compilers produce the CEEUOPT CSECT for the PLIXOPT string.

If more than one external procedure in a job declares PLIXOPT as STATIC EXTERNAL, only the first link-edited string is available at run time.

If the PLIXOPT string is specified in an OS PL/I main procedure, the options in the string are processed as if specified in the CEEUOPT CSECT. However, mixing a user-provided CEEUOPT with PLIXOPT is not recommended.

Options specified in the PARM parameter override those specified in the PLIXOPT string.