In the case of input messages of socket applications, a corresponding protocol header must be set up in the partner application, and this must precede each message segment or fragment. The protocol header is truncated and not transferred to the program unit.
The following applies to the data that comes after the protocol header:
If a service is to be started with a message sent to openUTM, the TAC must be at the beginning of the message.
If the message is to be inserted in the message queue of a TAC queue or of a temporary queue, the name of the queue must be at the beginning of the message. If the message goes to a temporary queue, there must be no TAC or LTERM in the application under the name of the temporary queue.
If the TAC is shorter than eight characters, it must be separated from the rest of the message by at least one blank.
If the specified TAC or the name of the queue is invalid, the BADTACS event service is started (provided it has been generated). If not, message K009 is sent to the socket application, unless a separate message module in used in which PARTNER has not been generated as the message destination for message K009.
If the TS application starts a service then this service can read the message (segments) or messages with the KDCS call MGET or FGET. If the TS application sends one or more messages to a service-controlled queue then any service can read the message (segments) or messages with the KDCS call DGET. The following then applies.
If the KCLA length is shorter than the length of the message segment at the MGET call, only the requested part is read; the rest of the message is not lost, however. The return code 02Z indicates that the message segment has not been read in its entirety. The rest of the message segment can be read with the next read call, another message segment with the next read call but one, and so on.
If the KCLA length is shorter than the length of the message segment at the DGET/FGET call, only the requested part is read; the rest of the message is lost. The return code 01Z indicates that the message segment has not been read in its entirety. A further message segment is read with the next read call.
If all the message segments are read, this is indicated by the return code 10Z.
If no code conversion has been generated for the connection to the socket partner (PTERM or TPOOL statement, operand MAP=USER), then the socket application must supply the name of the queue or queues in the "correct" code for the UTM application, i.e. in EBCDIC for a UTM(BS2000) application and in ASCII for a UTM application on Unix, Linux or Windows systems.