IBM SC34-6814-04 - Manual (Page 142)

UERCPURG
Task purged during XPI call.
XPI calls
All can be used.
API and SPI calls
All except EXEC CICS SHUTDOWN and EXEC CICS XCTL can be used.
Note:
1. Take care when issuing recursive commands not to cause a loop. For
example, it is your responsibility to avoid entering a loop when a file
control request is issued from the XFCSREQC exit. Use of the recursion
counter UEPRECUR is recommended.
2. Exit programs that issue EXEC CICS commands must first address the
EIB. See “Using CICS services” on page 4.
3. Exit programs that issue EXEC CICS commands, and that use the
DFHEIENT macro, should use the DFHEIRET macro to set a return code
and return to CICS. See “Returning values to CICS” on page 10.
The DFH$REQC sample global user exit program: DFH$REQC provides
sample processing for the file control state program global user exit, XFCSREQC.
The exit program, if enabled at the XFCSREQC exit point, is invoked after a file
ENABLE, DISABLE, OPEN, CLOSE, or CANCEL CLOSE request has been acted
on.
There is more information about using the sample program in the comments in the
DFH$REQC source code. In summary, DFH$REQC performs the following
processing :
1. Checks whether an open request for a VSAM data set has been acted on and
that the ACB error flag (ACBERFLG) is non zero.
2. If all are true, performs default processing. The ACBERFLG error code is
checked. If it is equal to X'74', the following message and data areas are built
into 690 bytes of contiguous storage, in such a way that they conform to the
editing rules of the WRITE OPERATOR command:
Message
VSAM Open error has occurred — VSAM error flag X’nn’
The ACBERFLG error code is converted from hex to character format and
appended to the end of the message.
Access method control block (ACB)
The data starts with an 'ACB' eye-catcher. All the data within the ACB is
converted into character format and added after the eye-catcher.
Exec Interface Block (EIB)
The data starts with an 'EIB' eye-catcher. All the data within the EIB is
converted into character format and added after the eye-catcher.
Parameter list passed to the exit program
The data starts with a 'PLIST' eye-catcher. Only the exit-specific parameters
are converted to character format and added after the eye-catcher.
File Information
The data starts with a 'FINFO' eye-catcher. This is followed by the
8-character file name and the 44-character dsname of the data set
120 Customization Guide