GN call
If an input message contains more than one segment, a Get Unique (GU) call retrieves the first segment of the message and Get Next (GN) calls retrieve the remaining segments.
Format
>>-GN--+-i/o_pcb-+--i/o_area----------------------------------->< '-aib-----'
| Call Name | DB/DC | DBCTL | DCCTL | DB Batch | TM Batch |
|---|---|---|---|---|---|
| GN | X | X |
Parameters
- i/o pcb
- Specifies the I/O PCB, the first PCB address in the list that is passed to the program. This parameter is an input and output parameter.
- aib
- Specifies the application interface block (AIB) that is used for
the call. This parameter is an input and output parameter. The following fields must be initialized in the AIB:
- AIBID
- Eye catcher. This 8-byte field must contain DFSAIBbb.
- AIBLEN
- AIB lengths. This field must contain the actual length of the AIB that the application program obtained.
- AIBRSNM1
- Resource name. This 8-byte, left-justified field must contain the PCB name IOPCBbbb.
- AIBOALEN
- I/O area length. This field must contain the length of the I/O area that is specified in the call list.
- i/o area
- Specifies the I/O area to use for this call. This parameter is an output parameter. The I/O area must be large enough to hold the largest segment passed between the program and IMS™ TM.
Usage
If you are processing messages that contain more than one segment, you use the GN call to retrieve the second and subsequent segments of the message. IMS TM returns one message segment to the I/O area of your application program each time the application program issues a GN call.
You can issue a GN call from a BMP program.
Restrictions
The AIB must specify the I/O PCB for this call.
You cannot issue a GN call from a CPI-C driven application program.