Parameters you can use in any Language Processor Environment

There are several parameters that you can specify in any language processor environment. That is, you can use these parameters in environments that are integrated into TSO/E and in environments that are not integrated into TSO/E. The following describes the parameters and any considerations for specifying them.

LANGUAGE

The language code. The default is ENU for US English in mixed case (upper and lowercase).

PARSETOK

The token for the PARSE SOURCE instruction. The default is a blank.

ADDRSPN

The name of the address space. TSO/E provides the following defaults:

IRXPARMS – MVS™
IRXTSPRM – TSO/E
IRXISPRM – ISPF

You can change the address space name for any type of language processor environment. If you write applications that examine the PARMBLOCK for an environment and perform processing based on the address space name, you must ensure that any changes you make to the ADDRSPN field do not affect your application programs.

FLAGS

The FLAGS field is a fullword of bits that are used as flags. You can specify any of the flags in any environment. However, the value you specify for each flag depends on the purpose of the flag. In addition, there are some restrictions for various flag settings depending on the flag setting in the previous environment.

The following explains the different considerations for the setting of some flags. See Characteristics of a Language Processor Environment for details about each flag.

Note: If your installation uses ISPF, there are several considerations about the flag settings for language processor environments that are initialized for ISPF. For more information, see Flag settings for environments initialized for TSO/E and ISPF .

TSOFL

The TSOFL flag indicates whether the new environment is integrated into TSO/E.

If IRXINIT is initializing an environment in a non-TSO/E address space, the flag must be off (set to 0). The TSOFL flag must also be off if the environment is being initialized as a reentrant environment. You can initialize reentrant environments only by explicitly calling the IRXINIT routine.

If IRXINIT is initializing an environment in the TSO/E address space, the TSOFL flag can be on or off. If the flag is on, the environment is integrated into TSO/E. REXX execs that run in the environment can use TSO/E commands, such as ALLOCATE and PRINTDS, and TSO/E programming services that are described in z/OS TSO/E Programming Services (for example, the parse service routine and TSO/E I/O service routines, such as PUTGET). The exec can also use ISPF services and can call and be called by TSO/E CLISTs.

If the flag is off, the environment is not integrated into TSO/E. In this case, REXX execs cannot use TSO/E commands, TSO/E programming services, or ISPF services, or interact with CLISTs. If the exec contains these type of services, unpredictable results can occur.

If the TSOFL flag is on (the environment is integrated into TSO/E), then:

The RENTRANT flag must be off (set to 0)
The names of the replaceable routines in the module name table must be blank. You cannot provide replaceable routines in environments that are integrated into TSO/E.
Note that the module name table also includes several fields for the names of REXX exit routines (for example, EXECINIT, ATTNROUT, IRXEXECX, and EXECTERM). If the environment is integrated into TSO/E (TSOFL flag is on), you can specify the exits in the module name table.
The INDD and OUTDD fields in the module name table must be the defaults SYSTSIN and SYSTSPRT
The subpool number in the SUBPOOL field must be 78, in decimal.

The TSOFL flag cannot be on (set to 1) if a previous language processor environment in the environment chain has the TSOFL flag off.

NEWSTKFL

The NEWSTKFL flag indicates whether IRXINIT initializes a new data stack for the new environment.

If you set the NEWSTKFL off for the new environment that IRXINIT is initializing, you must ensure that the SPSHARE flag is on in the previous environment. The SPSHARE flag determines whether the subpool is shared across MVS tasks. If the NEWSTKFL flag is off for the new environment and the SPSHARE flag is off in the previous environment, an error occurs when IRXINIT tries to initialize the new environment.

Module Name Table

The module name table contains the ddnames for reading and writing data and for loading REXX execs, and the names of replaceable routines and exit routines. The fields you can specify in any address space are described below. You can use the replaceable routines only in:

Non-TSO/E address spaces
The TSO/E address space if the language processor environment is initialized with the TSOFL flag off (the environment is not integrated with TSO/E).

The module name table also contains fields for several REXX exits. The fields are EXECINIT for the exec initialization exit, ATTNROUT for the attention handling exit, IRXEXECX for the exec processing exit (for the IRXEXEC routine), and EXECTERM for the exec termination exit. You can specify exits for exec initialization (EXECINIT), exec processing (IRXEXECX), and exec termination (EXECTERM) in any type of language processor environment. You can provide an attention handling exit (ATTNROUT) only for environments that are integrated into TSO/E.

LOADDD

The name of the DD from which the system loads REXX execs. The default TSO/E provides in all three parameters modules is SYSEXEC. (See Using SYSPROC and SYSEXEC for REXX execs for more information about SYSEXEC in the TSO/E address space).

The DD from which the system loads REXX execs depends on the name specified in the LOADDD field and the setting of the TSOFL and NOLOADDD flags. If the TSOFL flag is on, the language processor environment is initialized in the TSO/E address space and is integrated into TSO/E (see Flags and corresponding masks). In TSO/E, you can store REXX execs in data sets that are allocated to SYSPROC or to the DD specified in the LOADDD field (the default is SYSEXEC). The NOLOADDD flag (see Flags and corresponding masks) indicates whether the system searches SYSPROC only or whether the system searches the DD specified in the LOADDD field (SYSEXEC) first, followed by SYSPROC.

If the TSOFL flag is off, the system loads REXX execs from the DD specified in the LOADDD field.

Note: For the default parameters modules IRXTSPRM and IRXISPRM, the NOLOADDD flag is off (0). Therefore, the system searches SYSEXEC followed by SYSPROC. To have the system search SYSPROC exclusively, you can provide your own parameters module. TSO/E users can also use the EXECUTIL command to dynamically change the search order. EXECUTIL describes the EXECUTIL command.

The system opens the specified DD the first time a REXX exec is loaded. The DD remains open until the environment under which it was opened is terminated. If you want the system to close the DD after each REXX exec is fetched, you must set the CLOSEXFL flag on (see Flags and corresponding masks). Users can also use the EXECUTIL command to dynamically close the DD. Note that the system may close the data set at certain points.

See Using SYSPROC and SYSEXEC for REXX execs for more information about SYSPROC and SYSEXEC.

EXECINIT

The name of an exit routine that gets control after the system initializes the REXX variable pool for a REXX exec, but before the language processor starts processing the exec.

IRXEXECX

The name of an exit routine that is invoked whenever the IRXEXEC routine is called.

EXECTERM

The name of an exit routine that is invoked after a REXX exec has completed processing, but before the system terminates the REXX variable pool.

Host Command Environment Table

The table contains the names of the host command environments that are valid for the language processor environment and the names of the routines that the system calls to process commands for the host command environment.

When IRXINIT creates the host command environment table for a new language processor environment, IRXINIT checks the setting of the NEWSCFL flag. The NEWSCFL flag indicates whether the host command environments that are defined for the previous language processor environment are added to the table that is specified for the new environment. If the NEWSCFL flag is 0, IRXINIT creates the table by copying the host command environment table from the previous environment and concatenating the entries specified for the new environment. If the NEWSCFL flag is 1, IRXINIT creates the table using only the entries specified for the new environment.

Function Package Table

The function package table contains information about the user, local, and system function packages that are available in the language processor environment. Function package table describes the format of the table in detail.

When IRXINIT creates the function package table for a new language processor environment, IRXINIT checks the settings of the USERPKFL, LOCPKFL, and SYSPKFL flags. The three flags indicate whether the user, local, and system function packages that are defined for the previous language processor environment are added to the function package table that is specified for the new environment. If a particular flag is 0, IRXINIT copies the function package table from the previous environment and concatenates the entries specified for the new environment. If the flag is 1, IRXINIT creates the function package table using only the entries specified for the new environment.