MFX provides a number of special REXX variables to facilitate the development of REXX exits. These variables offer a simple, efficient means of establishing communication between the exit and the sort/merge.
To load these variables, the following command must be used when the exit is called.
ADDRESS 'SYNCREXX' 'GIVE'
When the exit completes its work, the exit should use the following sequence of commands to return the variables to MFX.
ADDRESS 'SYNCREXX' 'TAKE' RETURN
The following table describes the special REXX variables.
Table 1. REXX Variables Provided by MFX
|
Variable
|
Function
|
|
SYRECORD
|
When the exit is entered, SYRECORD contains the current data record.
The exit can accept the record, modify it or add a new record;
SYACTION should be set accordingly.
If SYRECORD is null, then MFX has no data remaining. When this
happens, the exit can either CLOSE or continue to INSERT new
records.
|
|
SYACTION
|
This variable must be set before the exit returns control to MFX. It
describes the disposition of the current record. Possible values for
SYACTION are as follows:
ACCEPT: Retain the current record with no modification.
REPLACE: Replace the current record with the contents of the
SYRECORD.
DELETE: Delete the current record.
INSERT: Insert the contents of the SYRECORD before the current
record.
CLOSE: Do not return to the exit.
ABEND: Terminate MFX.
If an E15 is providing all the input (SORTIN not present), the only
valid values for SYACTION are INSERT, CLOSE or ABEND.
|
|
SYEXITYP
|
This variable will automatically be set to E15 or E35, depending on
which type of exit is being called.
|
|
SYGBLN1...
...SYGBLN8
|
These eight special variables are global variables. You can set these
to any value provided that the value does not exceed 15 characters
in length. MFX will insure that these variables are preserved across
calls to the exit.
|
|
SYGBLSTR
|
This is an additional global variable. You can set this to any value,
provided the string does not exceed 1024 characters in length. MFX
will insure that this variable is preserved across calls to the
exit.
|
|