EMS Manual

Retrieving Event Messages Programmatically

EMS Manual—426909-005

4-16

Extracting Tokens From the Response (SSGET)

At the highest level, the GETEVENT response includes only a few basic tokens,

among them the event message itself. To extract these tokens from the response

buffer, use the SSGET procedure. (For a description of SSGET, see the SPI

Programming Manual.)



ZSPI^TKN^RETCODE. The return token is used to report the overall result of the

command processing, as it is for all other subsystem command-response

interfaces. A nonzero value means that a serious error has occurred. A value of

zero indicates that the command completed without errors. However, a warning

might have been issued (for example, an end-of-file warning, as described in

Obtaining an Event Message (GETEVENT) on page 4-12 under

ZEMS^TKN^EOFSTOP).



ZEMS^TKN^EVENT (nonshared). This token contains the event message you

requested by issuing the GETEVENT command message.



ZSPI^TKN^CONTEXT. This token contains the current distributor context, as

described in Obtaining an Event Message (GETEVENT) on page 4-12.



ZEMS^TKN^PASSVAL (nonshared). If the filter executed a PASS statement that

included a pass value (for example, PASS 3), the PASSVAL token contains the

pass value. If the filter executed a simple PASS statement (with no specified

value), this token is not present.

For example, to extract the event message from the response buffer:

spi^error := SSGETTKN(spibuffer,

ZEMS^TKN^EVENT,

emsbuffer, !an integer array

1);

! Handle any error from SPI procedure

IF spi^error <> ZSPI^ERR^OK THEN ...

! Reset buffer length to what you declared for evtbuffer

@evtbuffer := @emsbuffer '+' 1; !skip over length field

spi^error := SSPUTTKN(evtbuffer,

ZSPI^TKN^RESET^BUFFER,

ZEMS^VAL^BUFLEN);

! See if anything wrong with evtbuffer

IF spi^error <> ZSPI^ERR^OK THEN ...

Extracting Tokens From the Event Message (EMSGET)

To extract tokens from an event message, use the EMSGET procedure. For a detailed

description, see Section 15, EMS Procedures

. EMSGET is analogous to SSGET, but

EMSGET retrieves tokens from event messages. SSGET retrieves tokens from

command and response messages.