Accessing the command-level parameter structure from exits XFCREQ and XFCREQC
The command-level parameter structure consists of a series of addresses. The first address points to the EXEC interface descriptor (EID), which consists of a bit string that describes the type of request and identifies each keyword specified with the request. The remaining addresses point to pieces of data associated with the request. For example, the second address always points to the file name.
Only the first 8 addresses and the last address can be referenced by the user exit. The ninth through eleventh addresses are reserved for CICS® internal use.
You can examine the EID to determine the type of request and the keywords specified. You can examine the other parameters in the list to determine the values of the keywords. You can also modify values of keywords specified on the request. (For example, you could change the name of the file involved in the request.)
End of parameter list indicator
The high-order bit is set on in the last address set in the parameter list to indicate that it is the last one in the list. On return from your user exit program, CICS scans the parameter list for the high-order bit to find the last parameter. Therefore, if you modify the length of the parameter list, you must also reset the high-order bit to indicate which is the new last address.
The original parameter list, as it was before XFCREQ was invoked, is restored after the completion of XFCREQC. It follows that the execution diagnostic facility (EDF) displays the original command before and after execution.