How to get native ora error for xa XAER_RMERR?

Hi all, I need some help trying to get back error codes.

I'm using the oracle xa interface for 2 phase commit, and I'm using it in C, not with jdbc.

What I'm looking for is the C equivalent for the jdbc method getOracleError() from the class oracle.jdbc.xa.OracleXAException

Using C and oci, I use xaoEnv and xaoSvcCtx to get the needed handles, but can't find a way to either get the corresponding error handle or some function to obtain the native error code when I get an XAER_RMERR. For example, I'm tracing the xa client and see this:
...

172952.39538.1:
xaoprepare: xid=0x3e8-010203-01, rmid=1, flags=0x0

172952.39538.1:
OCITransPrepare: Attempting

172952.39538.1:
ORA-02091: transaction rolled back
ORA-02290: check constraint
(J15USER7.SYS_C00570619) violated

172952.39538.1:
xaoprepare: rtn -3

...

This last -3 is what xa_prepare returns and is XAER_RMERR. What I'm trying to get at is the ora-02091 and ora-02290 that appear in the trace file and using jdbc I can get with the getOracleError function, but using C and OCI functions.

In other words, I want to do better than a generic XAER_RMERR code.

Any help will be appreciated.
Michael

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UC Irvine Database Research Group  444 Computer Science, 
On loan to the University of       U. of California at Irvine,
California, Irvine (Researcher)    Irvine, CA, 92697-3425