Command Arguments Passed To Rexx Programs; Command Arguments Passed To Assembler Programs - IBM SC34-5764-01 Manual

Command Definition
authorized user to use DEFSCMD to change command definitions that affect other REXX/CICS users. See
section "DEFCMD" on page 332 for more information on the DEFCMD command and section "DEFSCMD"
on page 335 for more information on the DEFSCMD command.

Command Arguments Passed to REXX Programs

When a REXX/CICS command is written in REXX and that command is used, the REXX program (defined
by DEFCMD or DEFSCMD) is either invoked or awakened (from a WAITREQ induced "sleep"). If it is
invoked, then the command string is passed as an argument to the exec. Also, if it is invoked, the very first
WAITREQ command issued (if any) falls through immediately, with the command string being placed in the
REXX variable REQUEST. If the REXX exec was already started earlier and waiting for a request (due to
an earlier WAITREQ command) then the command string is only placed in the REXX variable REQUEST.
Note: Command programs written in REXX can easily get and set the contents of REXX variables in the
REXX exec that caused them to be invoked, by using the C2S and S2C commands. See section
"C2S" on page 331 for more information on the C2S command and section "S2C" on page 373 for
more information on the S2C command.

Command Arguments Passed to Assembler Programs

In addition to the REXX language, REXX/CICS command programs may be written in assembler
language. Assembler language routines must exist in a CICS program properly defined (for example, by
using the CEDA DEFINE PROGRAM command). These programs are invoked by an EXEC CICS LINK if
the CICSLINK option was specified on the DEFCMD or DEFSCMD commands. If the DEFCMD or
DEFSCMD, on the other hand, specifies the CICSLOAD option, then the program is EXEC CICS LOADed
by the first command that causes it to be invoked for the current CICS task, and its load address is
remembered. Any subsequent commands in the same CICS task that use this program performs a direct
branch entry (by an assembler BASSM instruction) into the program. It is recommended that these
assembler programs return control by an assembler BSM instruction so that the correct mode switching (if
any) occurs.
The following describes the contents of the registers when an assembler language command program gets
control, and it describes the parameters upon entry to these programs.
Entry Specifications when DEFCMD CICSLOAD is specified:
When the code for the command program gets control by a direct branch, the contents of the registers
are:
Register 0
Unpredictable
Register 1
Address of the CICPARMS control block
Registers 2-12
Unpredictable
Register 13
Address of 18 fullword register save area
Register 14
Return address
Register 15
Entry point address
Before the program returns to the caller, it should place the return code it wants reflected into the
CICPARMS RETCODE field.
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CICS TS for VSE/ESA: REXX Guide